/**
 * ChordSphere — Apple-Inspired Design System
 *
 * Design tokens inspired by Apple's Human Interface Guidelines.
 * All classes use BEM notation with the .cs- prefix.
 *
 * Color palette:
 *   Primary:    #007AFF (system blue)
 *   Background: #f5f5f7
 *   Surface:    #ffffff
 *   Text:       #1d1d1f
 *   Secondary:  #86868b
 *   Success:    #34C759
 *   Warning:    #FF9500
 *   Danger:     #FF3B30
 */

/* ==========================================================================
   CSS Custom Properties
   ========================================================================== */

:root {
    --cs-primary: #007AFF;
    --cs-primary-hover: #0066d6;
    --cs-primary-light: rgba(0, 122, 255, 0.08);
    --cs-bg: #f5f5f7;
    --cs-surface: #ffffff;
    --cs-text: #1d1d1f;
    --cs-text-secondary: #86868b;
    --cs-text-tertiary: #aeaeb2;
    --cs-border: rgba(0, 0, 0, 0.06);
    --cs-border-strong: rgba(0, 0, 0, 0.12);
    --cs-success: #34C759;
    --cs-success-light: rgba(52, 199, 89, 0.1);
    --cs-warning: #FF9500;
    --cs-warning-light: rgba(255, 149, 0, 0.1);
    --cs-danger: #FF3B30;
    --cs-danger-light: rgba(255, 59, 48, 0.08);
    --cs-info: #5AC8FA;
    --cs-info-light: rgba(90, 200, 250, 0.1);
    --cs-radius-xs: 6px;
    --cs-radius-sm: 8px;
    --cs-radius: 12px;
    --cs-radius-lg: 16px;
    --cs-radius-xl: 20px;
    --cs-radius-full: 980px;
    --cs-shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --cs-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
    --cs-shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.08);
    --cs-shadow-xl: 0 12px 40px rgba(0, 0, 0, 0.12);
    --cs-font: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'SF Pro Display', 'Helvetica Neue', Arial, sans-serif;
    --cs-transition: 0.2s ease;
    --cs-nav-height: 52px;
}

/* ==========================================================================
   Reset
   ========================================================================== */

*, *::before, *::after {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

img {
    max-width: 100%;
    height: auto;
}

a {
    color: inherit;
    text-decoration: none;
}

button {
    font-family: inherit;
}

/* ==========================================================================
   Base Typography
   ========================================================================== */

.cs-body {
    font-family: var(--cs-font);
    font-size: 17px;
    line-height: 1.47059;
    color: var(--cs-text);
    background: var(--cs-bg);
    letter-spacing: -0.022em;
}

.cs-body--auth {
    background: var(--cs-bg);
}

.cs-main {
    font-family: var(--cs-font);
    font-size: 17px;
    line-height: 1.47059;
    color: var(--cs-text);
    background: var(--cs-bg);
    min-height: 100vh;
    letter-spacing: -0.022em;
}

h1, h2, h3, h4, h5, h6 {
    margin-top: 0;
    color: var(--cs-text);
    letter-spacing: -0.022em;
}

h1 { font-size: 2rem; font-weight: 700; line-height: 1.15; letter-spacing: -0.028em; }
h2 { font-size: 1.5rem; font-weight: 600; line-height: 1.2; letter-spacing: -0.024em; }
h3 { font-size: 1.25rem; font-weight: 600; line-height: 1.25; }
h4 { font-size: 1.1rem; font-weight: 600; line-height: 1.3; }

/* ==========================================================================
   Layout
   ========================================================================== */

.cs-container {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 max(1.5rem, env(safe-area-inset-left));
}

.cs-container-narrow {
    max-width: 760px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.cs-container-wide {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ==========================================================================
   Header / Navigation
   ========================================================================== */

.cs-header {
    background: rgba(251, 251, 253, 0.8);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--cs-border);
    position: sticky;
    top: 0;
    z-index: 100;
    height: var(--cs-nav-height);
}

.cs-header__inner {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.cs-header__left {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.cs-header__logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--cs-text);
    font-weight: 600;
    font-size: 1.05rem;
    letter-spacing: -0.02em;
    flex-shrink: 0;
}

.cs-header__logo img {
    height: 28px;
    width: auto;
}

.cs-header__logo-text {
    font-weight: 600;
}

.cs-header__nav {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.cs-header__nav-link {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.375rem 0.75rem;
    border-radius: var(--cs-radius-sm);
    font-size: 0.9375rem;
    font-weight: 400;
    color: var(--cs-text);
    text-decoration: none;
    transition: background var(--cs-transition), color var(--cs-transition);
    letter-spacing: -0.01em;
}

.cs-header__nav-link:hover {
    background: rgba(0, 0, 0, 0.04);
}

.cs-header__nav-link--active {
    color: var(--cs-primary);
    font-weight: 500;
}

.cs-header__nav-link--admin {
    color: var(--cs-text-secondary);
}

.cs-header__right {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.cs-header__auth-links {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.cs-header__user-menu {
    position: relative;
}

.cs-header__user-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: none;
    border: none;
    padding: 0.375rem 0.625rem;
    border-radius: var(--cs-radius-full);
    cursor: pointer;
    font-size: 0.9375rem;
    color: var(--cs-text);
    transition: background var(--cs-transition);
}

.cs-header__user-toggle:hover {
    background: rgba(0, 0, 0, 0.04);
}

.cs-header__user-name {
    font-weight: 500;
}

.cs-header__chevron {
    font-size: 0.6rem;
    color: var(--cs-text-secondary);
    transition: transform var(--cs-transition);
}

.cs-header__dropdown {
    position: absolute;
    top: calc(100% + 6px);
    right: 0;
    background: var(--cs-surface);
    border-radius: var(--cs-radius);
    box-shadow: var(--cs-shadow-xl);
    border: 1px solid var(--cs-border);
    min-width: 200px;
    padding: 0.375rem;
    z-index: 50;
    display: none;
    opacity: 0;
    transform: translateY(-4px) scale(0.98);
    transition: opacity 0.15s ease, transform 0.15s ease;
}

.cs-header__dropdown.cs-open {
    display: block;
    opacity: 1;
    transform: translateY(0) scale(1);
}

.cs-header__dropdown-item {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
    color: var(--cs-text);
    text-decoration: none;
    border-radius: var(--cs-radius-xs);
    transition: background var(--cs-transition);
}

.cs-header__dropdown-item:hover {
    background: rgba(0, 0, 0, 0.04);
}

.cs-header__dropdown-item--danger {
    color: var(--cs-danger);
}

.cs-header__dropdown-divider {
    height: 1px;
    background: var(--cs-border);
    margin: 0.25rem 0;
}

/* Mobile nav toggle */
.cs-nav-toggle,
.cs-header__nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--cs-text);
    font-size: 1.25rem;
    cursor: pointer;
    padding: 0.375rem;
    line-height: 1;
    border-radius: var(--cs-radius-sm);
}

/* ==========================================================================
   Auth Pages
   ========================================================================== */

.cs-auth-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 3rem 1.5rem;
    background: var(--cs-bg);
}

.cs-auth-header {
    text-align: center;
    margin-bottom: 2rem;
}

.cs-auth-logo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
    text-decoration: none;
    color: var(--cs-text);
}

.cs-auth-logo__title {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--cs-text);
}

.cs-auth-logo__subtitle {
    font-size: 0.9375rem;
    color: var(--cs-text-secondary);
    font-weight: 400;
}

.cs-auth-card {
    background: var(--cs-surface);
    border-radius: var(--cs-radius-xl);
    padding: 2.5rem;
    width: 100%;
    max-width: 400px;
    box-shadow: var(--cs-shadow-lg);
    border: 1px solid var(--cs-border);
}

.cs-auth-card__title {
    font-size: 1.5rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 1.75rem;
    letter-spacing: -0.024em;
}

.cs-auth-card__links {
    text-align: center;
    margin-top: 1.25rem;
    font-size: 0.875rem;
}

.cs-auth-card__link {
    color: var(--cs-primary);
    font-weight: 400;
    text-decoration: none;
}

.cs-auth-card__link:hover {
    text-decoration: underline;
}

.cs-auth-card__alt {
    text-align: center;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--cs-border);
    font-size: 0.875rem;
    color: var(--cs-text-secondary);
}

.cs-auth-card__alt a {
    color: var(--cs-primary);
}

.cs-auth-card__alt a:hover {
    text-decoration: underline;
}

.cs-auth-footer {
    text-align: center;
    margin-top: 2rem;
    font-size: 0.8125rem;
    color: var(--cs-text-tertiary);
}

/* ==========================================================================
   Forms
   ========================================================================== */

.cs-form {
    width: 100%;
}

.cs-form__group {
    margin-bottom: 1.25rem;
}

.cs-form__label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--cs-text);
    margin-bottom: 0.375rem;
}

.cs-form__input,
.cs-form__textarea,
.cs-form__select,
/* Legacy flat-name support */
.cs-input,
.cs-textarea,
.cs-select {
    display: block;
    width: 100%;
    padding: 0.625rem 0.875rem;
    font-size: 1rem;
    font-family: inherit;
    color: var(--cs-text);
    background: var(--cs-surface);
    border: 1px solid var(--cs-border-strong);
    border-radius: var(--cs-radius-sm);
    transition: border-color var(--cs-transition), box-shadow var(--cs-transition);
    outline: none;
    letter-spacing: -0.01em;
}

.cs-form__input:focus,
.cs-form__textarea:focus,
.cs-form__select:focus,
.cs-input:focus,
.cs-textarea:focus,
.cs-select:focus {
    border-color: var(--cs-primary);
    box-shadow: 0 0 0 3px var(--cs-primary-light);
}

.cs-form__input::placeholder,
.cs-form__textarea::placeholder,
.cs-input::placeholder,
.cs-textarea::placeholder {
    color: var(--cs-text-tertiary);
}

.cs-form__textarea,
.cs-textarea {
    resize: vertical;
    min-height: 100px;
}

.cs-form__select,
.cs-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2386868b' d='M6 8.5L1 3.5h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    padding-right: 2.5rem;
    cursor: pointer;
}

.cs-form__input--error {
    border-color: var(--cs-danger);
}

.cs-form__input--error:focus {
    box-shadow: 0 0 0 3px var(--cs-danger-light);
}

.cs-form__help {
    font-size: 0.8125rem;
    color: var(--cs-text-secondary);
    margin-top: 0.25rem;
}

.cs-form__error {
    font-size: 0.8125rem;
    color: var(--cs-danger);
    margin-top: 0.25rem;
}

.cs-form__actions {
    margin-top: 1.5rem;
}

.cs-form__row,
.cs-form-row {
    display: flex;
    gap: 1rem;
}

.cs-form__row .cs-form__group,
.cs-form-row .cs-form__group {
    flex: 1;
}

.cs-form--inline,
.cs-inline-form {
    display: flex;
    align-items: flex-end;
    gap: 0.75rem;
}

.cs-form--inline .cs-form__group,
.cs-inline-form .cs-form__group {
    margin-bottom: 0;
}

.cs-form__checkbox-group,
.cs-checkbox-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.cs-form__checkbox,
.cs-checkbox {
    width: 18px;
    height: 18px;
    accent-color: var(--cs-primary);
    cursor: pointer;
    border-radius: 4px;
}

.cs-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--cs-text);
    margin-bottom: 0.375rem;
}

.cs-label-optional {
    font-weight: 400;
    color: var(--cs-text-secondary);
    font-size: 0.8rem;
}

/* ==========================================================================
   Alerts
   ========================================================================== */

.cs-alert {
    padding: 0.875rem 1.125rem;
    border-radius: var(--cs-radius);
    font-size: 0.9375rem;
    margin-bottom: 1.25rem;
    line-height: 1.4;
}

.cs-alert--error {
    background: var(--cs-danger-light);
    color: #d70015;
}

.cs-alert--success {
    background: var(--cs-success-light);
    color: #248a3d;
}

.cs-alert--warning {
    background: var(--cs-warning-light);
    color: #9a6700;
}

.cs-alert--info {
    background: var(--cs-info-light);
    color: #0077b6;
}

.cs-alert__list {
    margin: 0.25rem 0 0;
    padding-left: 1.25rem;
}

.cs-alert__list li {
    margin-bottom: 0.125rem;
}

/* ==========================================================================
   Flash Messages
   ========================================================================== */

.cs-flash-container {
    max-width: 1120px;
    margin: 0 auto;
    padding: 1rem 1.5rem 0;
}

.cs-flash {
    padding: 0.875rem 1.25rem;
    border-radius: var(--cs-radius);
    font-size: 0.9375rem;
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.625rem;
    position: relative;
    animation: cs-flash-in 0.3s ease;
}

@keyframes cs-flash-in {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
}

.cs-flash--success {
    background: var(--cs-success-light);
    color: #248a3d;
}

.cs-flash--error {
    background: var(--cs-danger-light);
    color: #d70015;
}

.cs-flash--info {
    background: var(--cs-info-light);
    color: #0077b6;
}

.cs-flash--warning {
    background: var(--cs-warning-light);
    color: #9a6700;
}

/* Legacy flash classes (non-BEM) */
.cs-flash-success { background: var(--cs-success-light); color: #248a3d; }
.cs-flash-error { background: var(--cs-danger-light); color: #d70015; }
.cs-flash-info { background: var(--cs-info-light); color: #0077b6; }
.cs-flash-warning { background: var(--cs-warning-light); color: #9a6700; }

.cs-flash__dismiss,
.cs-flash-dismiss {
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    font-size: 1.125rem;
    cursor: pointer;
    color: inherit;
    opacity: 0.5;
    line-height: 1;
    padding: 0.25rem;
    border-radius: var(--cs-radius-xs);
    transition: opacity var(--cs-transition);
}

.cs-flash__dismiss:hover,
.cs-flash-dismiss:hover {
    opacity: 0.85;
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.cs-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.5rem 1.125rem;
    border: none;
    border-radius: var(--cs-radius-full);
    font-size: 0.9375rem;
    font-weight: 400;
    font-family: inherit;
    cursor: pointer;
    transition: background var(--cs-transition), opacity var(--cs-transition), transform 0.1s ease;
    user-select: none;
    text-decoration: none;
    line-height: 1.4;
    letter-spacing: -0.01em;
    white-space: nowrap;
}

.cs-btn:active {
    transform: scale(0.97);
}

.cs-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

.cs-btn--primary,
.cs-btn-primary {
    background: var(--cs-primary);
    color: #fff;
}

.cs-btn--primary:hover:not(:disabled),
.cs-btn-primary:hover:not(:disabled) {
    background: var(--cs-primary-hover);
}

.cs-btn--secondary,
.cs-btn-secondary {
    background: rgba(0, 0, 0, 0.05);
    color: var(--cs-text);
}

.cs-btn--secondary:hover:not(:disabled),
.cs-btn-secondary:hover:not(:disabled) {
    background: rgba(0, 0, 0, 0.08);
}

.cs-btn--danger,
.cs-btn-danger {
    background: var(--cs-danger);
    color: #fff;
}

.cs-btn--danger:hover:not(:disabled),
.cs-btn-danger:hover:not(:disabled) {
    background: #e0342a;
}

.cs-btn--success {
    background: var(--cs-success);
    color: #fff;
}

.cs-btn--success:hover:not(:disabled) {
    background: #2db84e;
}

.cs-btn--outline,
.cs-btn-outline {
    background: transparent;
    border: 1px solid var(--cs-primary);
    color: var(--cs-primary);
}

.cs-btn--outline:hover:not(:disabled),
.cs-btn-outline:hover:not(:disabled) {
    background: var(--cs-primary-light);
}

.cs-btn--ghost,
.cs-btn-ghost {
    background: transparent;
    color: var(--cs-primary);
}

.cs-btn--ghost:hover:not(:disabled),
.cs-btn-ghost:hover:not(:disabled) {
    background: rgba(0, 0, 0, 0.04);
}

.cs-btn--sm,
.cs-btn-sm {
    padding: 0.3125rem 0.75rem;
    font-size: 0.8125rem;
}

.cs-btn--lg,
.cs-btn-lg {
    padding: 0.75rem 1.75rem;
    font-size: 1.0625rem;
}

.cs-btn--block,
.cs-btn-block {
    display: flex;
    width: 100%;
}

.cs-btn-group {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

/* ==========================================================================
   Cards
   ========================================================================== */

.cs-card {
    background: var(--cs-surface);
    border-radius: var(--cs-radius-lg);
    border: 1px solid var(--cs-border);
    overflow: hidden;
    transition: box-shadow var(--cs-transition);
}

.cs-card:hover {
    box-shadow: var(--cs-shadow);
}

.cs-card__header,
.cs-card-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--cs-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.cs-card__header h2,
.cs-card__header h3,
.cs-card-header h2,
.cs-card-header h3 {
    margin: 0;
    font-size: 1.1rem;
    font-weight: 600;
}

.cs-card__body,
.cs-card-body {
    padding: 1.5rem;
}

.cs-card__footer,
.cs-card-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--cs-border);
    background: rgba(0, 0, 0, 0.015);
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 0.75rem;
}

.cs-card__image,
.cs-card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

/* ==========================================================================
   Badges
   ========================================================================== */

.cs-badge {
    display: inline-flex;
    align-items: center;
    padding: 0.125rem 0.5rem;
    border-radius: var(--cs-radius-full);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0;
}

/* BEM modifier badges */
.cs-badge--primary,
.cs-badge-primary {
    background: var(--cs-primary-light);
    color: var(--cs-primary);
}

.cs-badge--success,
.cs-badge-success {
    background: var(--cs-success-light);
    color: #248a3d;
}

.cs-badge--warning,
.cs-badge-warning {
    background: var(--cs-warning-light);
    color: #9a6700;
}

.cs-badge--danger,
.cs-badge-danger {
    background: var(--cs-danger-light);
    color: #d70015;
}

.cs-badge--info,
.cs-badge-info {
    background: var(--cs-info-light);
    color: #0077b6;
}

.cs-badge--neutral,
.cs-badge-neutral {
    background: rgba(0, 0, 0, 0.05);
    color: var(--cs-text-secondary);
}

.cs-badge--free,
.cs-badge-free {
    background: var(--cs-success-light);
    color: #248a3d;
    font-weight: 600;
}

/* Difficulty badges */
.cs-badge--beginner {
    background: var(--cs-success-light);
    color: #248a3d;
}

.cs-badge--intermediate {
    background: var(--cs-warning-light);
    color: #9a6700;
}

.cs-badge--advanced {
    background: var(--cs-danger-light);
    color: #d70015;
}

/* Legacy data-attribute badges */
.cs-badge-difficulty[data-level="beginner"] {
    background: var(--cs-success-light);
    color: #248a3d;
}

.cs-badge-difficulty[data-level="intermediate"] {
    background: var(--cs-warning-light);
    color: #9a6700;
}

.cs-badge-difficulty[data-level="advanced"] {
    background: var(--cs-danger-light);
    color: #d70015;
}

/* ==========================================================================
   Progress Bars
   ========================================================================== */

.cs-progress {
    width: 100%;
    height: 6px;
    background: rgba(0, 0, 0, 0.06);
    border-radius: var(--cs-radius-full);
    overflow: hidden;
}

.cs-progress__bar {
    height: 100%;
    border-radius: var(--cs-radius-full);
    transition: width 0.5s ease;
}

.cs-progress__fill {
    height: 100%;
    border-radius: var(--cs-radius-full);
    background: var(--cs-primary);
    transition: width 0.5s ease;
}

/* Legacy */
.cs-progress-bar {
    height: 100%;
    border-radius: var(--cs-radius-full);
    background: var(--cs-primary);
    transition: width 0.5s ease;
}

.cs-progress--lg,
.cs-progress-lg {
    height: 10px;
}

.cs-progress--inline {
    display: inline-flex;
    width: auto;
}

.cs-progress__text {
    font-size: 0.8125rem;
    color: var(--cs-text-secondary);
    margin-top: 0.25rem;
}

.cs-progress__label,
.cs-progress-label {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.375rem;
    font-size: 0.8125rem;
}

.cs-progress-label-text {
    color: var(--cs-text-secondary);
}

.cs-progress-label-value {
    font-weight: 600;
    color: var(--cs-text);
}

/* ==========================================================================
   Stats Row / Dashboard
   ========================================================================== */

.cs-dashboard {
    padding: 2rem 0 3rem;
    max-width: 1120px;
    margin: 0 auto;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
}

.cs-dashboard__header {
    margin-bottom: 2rem;
}

.cs-dashboard__title {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.028em;
    margin: 0;
}

.cs-dashboard__subtitle {
    color: var(--cs-text-secondary);
    font-size: 1.0625rem;
    margin-top: 0.25rem;
}

.cs-dashboard__section {
    margin-bottom: 2.5rem;
}

.cs-dashboard__section-title {
    font-size: 1.375rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
    letter-spacing: -0.022em;
}

.cs-stats-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2.5rem;
}

.cs-stat-card {
    background: var(--cs-surface);
    border-radius: var(--cs-radius-lg);
    padding: 1.25rem 1.5rem;
    border: 1px solid var(--cs-border);
    transition: box-shadow var(--cs-transition);
}

.cs-stat-card:hover {
    box-shadow: var(--cs-shadow);
}

.cs-stat-card__icon {
    width: 36px;
    height: 36px;
    border-radius: var(--cs-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.125rem;
    margin-bottom: 0.75rem;
    background: var(--cs-primary-light);
    color: var(--cs-primary);
}

.cs-stat-card__icon--success {
    background: var(--cs-success-light);
    color: var(--cs-success);
}

.cs-stat-card__icon--warning {
    background: var(--cs-warning-light);
    color: var(--cs-warning);
}

.cs-stat-card__icon--info {
    background: var(--cs-info-light);
    color: var(--cs-info);
}

.cs-stat-card__body {
    display: flex;
    flex-direction: column;
}

.cs-stat-card__value,
.cs-stat-value {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--cs-text);
    line-height: 1.15;
    letter-spacing: -0.028em;
}

.cs-stat-card__label,
.cs-stat-label {
    font-size: 0.8125rem;
    color: var(--cs-text-secondary);
    margin-top: 0.125rem;
}

/* Legacy stat icon colors */
.cs-stat-icon { width: 36px; height: 36px; border-radius: var(--cs-radius-sm); display: flex; align-items: center; justify-content: center; font-size: 1.125rem; margin-bottom: 0.75rem; }
.cs-stat-icon-orange { background: var(--cs-warning-light); color: var(--cs-warning); }
.cs-stat-icon-gold { background: var(--cs-warning-light); color: #c98400; }
.cs-stat-icon-green { background: var(--cs-success-light); color: var(--cs-success); }
.cs-stat-icon-blue { background: var(--cs-primary-light); color: var(--cs-primary); }

/* Activity feed */
.cs-activity-feed {
    list-style: none;
    margin: 0;
    padding: 0;
}

.cs-activity-feed__item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.875rem 0;
    border-bottom: 1px solid var(--cs-border);
}

.cs-activity-feed__item:last-child {
    border-bottom: none;
}

.cs-activity-feed__icon {
    flex-shrink: 0;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--cs-primary-light);
    color: var(--cs-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
}

.cs-activity-feed__text {
    font-size: 0.9375rem;
    color: var(--cs-text);
    line-height: 1.4;
}

.cs-activity-feed__time {
    font-size: 0.8125rem;
    color: var(--cs-text-tertiary);
    margin-top: 0.125rem;
}

/* Quick actions */
.cs-quick-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

/* ==========================================================================
   Course Cards & Grid
   ========================================================================== */

.cs-courses {
    padding: 2rem 0 3rem;
    max-width: 1120px;
    margin: 0 auto;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
}

.cs-courses__header {
    margin-bottom: 2rem;
}

.cs-courses__title {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.028em;
    margin: 0;
}

.cs-course-grid {
    display: grid;
    gap: 1.25rem;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
}

.cs-course-grid--2col {
    grid-template-columns: repeat(2, 1fr);
}

.cs-course-grid--3col {
    grid-template-columns: repeat(3, 1fr);
}

.cs-course-card {
    background: var(--cs-surface);
    border-radius: var(--cs-radius-lg);
    border: 1px solid var(--cs-border);
    overflow: hidden;
    transition: box-shadow var(--cs-transition), transform var(--cs-transition);
    text-decoration: none;
    display: block;
    color: inherit;
}

.cs-course-card:hover {
    box-shadow: var(--cs-shadow-lg);
    transform: translateY(-1px);
}

.cs-course-card__thumb {
    position: relative;
    width: 100%;
    height: 180px;
    overflow: hidden;
    background: linear-gradient(135deg, #667eea, #764ba2);
}

.cs-course-card__image {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.cs-course-card__placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    color: rgba(255, 255, 255, 0.6);
}

.cs-course-card__body {
    padding: 1.25rem;
}

.cs-course-card__title {
    font-size: 1.0625rem;
    font-weight: 600;
    color: var(--cs-text);
    margin: 0 0 0.375rem;
    letter-spacing: -0.01em;
    line-height: 1.3;
}

.cs-course-card__meta {
    font-size: 0.8125rem;
    color: var(--cs-text-secondary);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.cs-course-card__duration {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.cs-course-card__excerpt {
    font-size: 0.875rem;
    color: var(--cs-text-secondary);
    line-height: 1.45;
    margin-bottom: 0.75rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.cs-course-card__footer {
    padding: 0.875rem 1.25rem;
    border-top: 1px solid var(--cs-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.8125rem;
}

/* Course detail */
.cs-course-detail {
    padding: 2rem 0;
    max-width: 1120px;
    margin: 0 auto;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
}

.cs-course-detail__header {
    margin-bottom: 2rem;
}

.cs-course-detail__title {
    font-size: 2rem;
    font-weight: 700;
    margin: 0 0 0.5rem;
    letter-spacing: -0.028em;
}

.cs-course-detail__meta {
    color: var(--cs-text-secondary);
    font-size: 0.9375rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.cs-course-detail__description {
    font-size: 1.0625rem;
    line-height: 1.5;
    color: var(--cs-text);
    margin-bottom: 2rem;
}

/* ==========================================================================
   Module & Lesson Lists
   ========================================================================== */

.cs-module-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.cs-module {
    background: var(--cs-surface);
    border-radius: var(--cs-radius-lg);
    border: 1px solid var(--cs-border);
    overflow: hidden;
}

.cs-module__header {
    padding: 1.125rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    transition: background var(--cs-transition);
}

.cs-module__header:hover {
    background: rgba(0, 0, 0, 0.015);
}

.cs-module__title {
    font-size: 1.0625rem;
    font-weight: 600;
    margin: 0;
    color: var(--cs-text);
}

.cs-module__meta {
    font-size: 0.8125rem;
    color: var(--cs-text-secondary);
}

.cs-module__lessons {
    border-top: 1px solid var(--cs-border);
}

.cs-lesson-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.cs-lesson-item {
    border-bottom: 1px solid var(--cs-border);
}

.cs-lesson-item:last-child {
    border-bottom: none;
}

.cs-lesson-item__link {
    display: flex;
    align-items: center;
    gap: 0.875rem;
    padding: 0.875rem 1.5rem;
    text-decoration: none;
    color: var(--cs-text);
    transition: background var(--cs-transition);
}

.cs-lesson-item__link:hover {
    background: rgba(0, 0, 0, 0.02);
}

.cs-lesson-item__link--locked {
    opacity: 0.5;
    pointer-events: none;
}

.cs-lesson-item__link--completed {
    color: var(--cs-text-secondary);
}

.cs-lesson-item__icon {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    flex-shrink: 0;
    background: rgba(0, 0, 0, 0.05);
    color: var(--cs-text-secondary);
}

.cs-lesson-item__icon--completed {
    background: var(--cs-success-light);
    color: var(--cs-success);
}

.cs-lesson-item__title {
    font-size: 0.9375rem;
    font-weight: 500;
}

.cs-lesson-item__duration {
    font-size: 0.8125rem;
    color: var(--cs-text-tertiary);
    margin-left: auto;
}

/* Lesson viewer */
.cs-lesson {
    padding: 2rem 0;
    max-width: 800px;
    margin: 0 auto;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
}

.cs-lesson__header {
    margin-bottom: 2rem;
}

.cs-lesson__title {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.028em;
    margin: 0 0 0.5rem;
}

.cs-lesson__meta {
    color: var(--cs-text-secondary);
    font-size: 0.875rem;
}

.cs-lesson__content {
    line-height: 1.6;
    font-size: 1.0625rem;
}

.cs-lesson__nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 3rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--cs-border);
}

/* Content blocks */
.cs-content-block {
    margin-bottom: 2rem;
}

.cs-content-block__title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.cs-content-block__body {
    line-height: 1.6;
}

/* ==========================================================================
   Enrollment Card
   ========================================================================== */

.cs-enrollment-card {
    background: var(--cs-surface);
    border-radius: var(--cs-radius-lg);
    border: 1px solid var(--cs-border);
    padding: 1.25rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: box-shadow var(--cs-transition);
}

.cs-enrollment-card:hover {
    box-shadow: var(--cs-shadow);
}

.cs-enrollment-thumb {
    width: 72px;
    height: 72px;
    border-radius: var(--cs-radius);
    object-fit: cover;
    flex-shrink: 0;
    background: linear-gradient(135deg, #667eea, #764ba2);
}

.cs-enrollment-info {
    flex: 1;
    min-width: 0;
}

.cs-enrollment-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--cs-text);
    margin: 0 0 0.25rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.cs-enrollment-meta {
    font-size: 0.8125rem;
    color: var(--cs-text-secondary);
    margin-bottom: 0.5rem;
}

/* ==========================================================================
   Tables
   ========================================================================== */

.cs-table-wrapper,
.cs-table-wrap {
    overflow-x: auto;
    border-radius: var(--cs-radius-lg);
    border: 1px solid var(--cs-border);
    background: var(--cs-surface);
}

.cs-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9375rem;
}

.cs-table thead th {
    background: rgba(0, 0, 0, 0.02);
    padding: 0.75rem 1rem;
    text-align: left;
    font-weight: 500;
    color: var(--cs-text-secondary);
    font-size: 0.8125rem;
    letter-spacing: 0;
    border-bottom: 1px solid var(--cs-border);
    white-space: nowrap;
}

.cs-table tbody td {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--cs-border);
    vertical-align: middle;
    color: var(--cs-text);
}

.cs-table tbody tr:last-child td {
    border-bottom: none;
}

.cs-table tbody tr:hover {
    background: rgba(0, 0, 0, 0.015);
}

.cs-table__actions,
.cs-table-actions {
    display: flex;
    gap: 0.5rem;
}

/* ==========================================================================
   Breadcrumbs
   ========================================================================== */

.cs-breadcrumb {
    display: flex;
    align-items: center;
    gap: 0.375rem;
    font-size: 0.8125rem;
    color: var(--cs-text-secondary);
    margin-bottom: 1rem;
    list-style: none;
    padding: 0;
    flex-wrap: wrap;
}

.cs-breadcrumb__item {
    display: flex;
    align-items: center;
    gap: 0.375rem;
}

.cs-breadcrumb__item + .cs-breadcrumb__item::before,
.cs-breadcrumb li + li::before {
    content: '';
    display: inline-block;
    width: 7px;
    height: 7px;
    border-right: 1.5px solid var(--cs-text-tertiary);
    border-top: 1.5px solid var(--cs-text-tertiary);
    transform: rotate(45deg);
    margin-right: 0.125rem;
}

.cs-breadcrumb a,
.cs-breadcrumb__link {
    color: var(--cs-primary);
    text-decoration: none;
}

.cs-breadcrumb a:hover,
.cs-breadcrumb__link:hover {
    text-decoration: underline;
}

.cs-breadcrumb__item--current,
.cs-breadcrumb-current {
    color: var(--cs-text);
    font-weight: 500;
}

/* ==========================================================================
   Empty States
   ========================================================================== */

.cs-empty-state,
.cs-empty {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--cs-text-secondary);
}

.cs-empty-state__icon,
.cs-empty-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    opacity: 0.35;
}

.cs-empty-state__text,
.cs-empty-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--cs-text);
    margin-bottom: 0.375rem;
}

.cs-empty-state__subtext,
.cs-empty-text {
    font-size: 0.9375rem;
    color: var(--cs-text-secondary);
    margin-bottom: 1.5rem;
    max-width: 360px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.45;
}

.cs-empty-state--compact {
    padding: 2rem 1rem;
}

/* ==========================================================================
   Page Headers
   ========================================================================== */

.cs-page-header {
    padding: 2rem 0 1rem;
    margin-bottom: 1.5rem;
}

.cs-page-header h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
    letter-spacing: -0.028em;
}

.cs-page-header p {
    color: var(--cs-text-secondary);
    margin: 0;
    font-size: 1.0625rem;
}

.cs-section {
    margin-bottom: 2.5rem;
}

.cs-section-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--cs-border);
    letter-spacing: -0.015em;
}

/* ==========================================================================
   Grid System
   ========================================================================== */

.cs-grid {
    display: grid;
    gap: 1.25rem;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
}

.cs-grid-2 {
    display: grid;
    gap: 1.25rem;
    grid-template-columns: repeat(2, 1fr);
}

.cs-grid-3 {
    display: grid;
    gap: 1.25rem;
    grid-template-columns: repeat(3, 1fr);
}

.cs-grid-4 {
    display: grid;
    gap: 1.25rem;
    grid-template-columns: repeat(4, 1fr);
}

.cs-detail-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.cs-detail-grid__label {
    font-size: 0.875rem;
    color: var(--cs-text-secondary);
}

.cs-detail-grid__value {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--cs-text);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.cs-footer {
    background: var(--cs-surface);
    border-top: 1px solid var(--cs-border);
    color: var(--cs-text-secondary);
    padding: 1.5rem 0;
    margin-top: 4rem;
    font-size: 0.8125rem;
}

.cs-footer__inner {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.cs-footer .cs-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.cs-footer__copyright {
    color: var(--cs-text-tertiary);
}

.cs-footer__powered {
    color: var(--cs-text-tertiary);
}

.cs-footer a {
    color: var(--cs-text-secondary);
    text-decoration: none;
}

.cs-footer a:hover {
    color: var(--cs-primary);
}

.cs-footer-links {
    display: flex;
    gap: 1.5rem;
    list-style: none;
    margin: 0;
    padding: 0;
}

/* ==========================================================================
   Sidebar Layout
   ========================================================================== */

.cs-layout-sidebar {
    display: flex;
    min-height: calc(100vh - var(--cs-nav-height));
}

.cs-sidebar {
    width: 250px;
    background: var(--cs-surface);
    border-right: 1px solid var(--cs-border);
    padding: 1.25rem 0;
    flex-shrink: 0;
}

.cs-sidebar-section {
    margin-bottom: 1.5rem;
}

.cs-sidebar-label {
    display: block;
    padding: 0 1.25rem;
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--cs-text-tertiary);
    margin-bottom: 0.375rem;
}

.cs-sidebar-link {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    padding: 0.5rem 1.25rem;
    color: var(--cs-text-secondary);
    text-decoration: none;
    font-size: 0.9375rem;
    transition: background var(--cs-transition), color var(--cs-transition);
    border-left: 2px solid transparent;
}

.cs-sidebar-link:hover {
    background: rgba(0, 0, 0, 0.03);
    color: var(--cs-text);
}

.cs-sidebar-link.cs-active {
    background: var(--cs-primary-light);
    color: var(--cs-primary);
    border-left-color: var(--cs-primary);
    font-weight: 500;
}

.cs-sidebar-content {
    flex: 1;
    padding: 2rem;
    overflow-y: auto;
}

/* ==========================================================================
   Links
   ========================================================================== */

.cs-link {
    color: var(--cs-primary);
    text-decoration: none;
    font-weight: 400;
}

.cs-link:hover {
    text-decoration: underline;
}

.cs-link--back {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.9375rem;
    color: var(--cs-primary);
    margin-bottom: 1rem;
}

.cs-link--back::before {
    content: '';
    display: inline-block;
    width: 7px;
    height: 7px;
    border-left: 1.5px solid currentColor;
    border-bottom: 1.5px solid currentColor;
    transform: rotate(45deg);
}

/* ==========================================================================
   Avatar
   ========================================================================== */

.cs-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8125rem;
    font-weight: 600;
    flex-shrink: 0;
}

.cs-avatar-lg {
    width: 56px;
    height: 56px;
    font-size: 1.125rem;
}

/* ==========================================================================
   Dropdown
   ========================================================================== */

.cs-dropdown {
    position: relative;
}

.cs-dropdown-menu {
    position: absolute;
    top: calc(100% + 4px);
    right: 0;
    background: var(--cs-surface);
    border-radius: var(--cs-radius);
    box-shadow: var(--cs-shadow-xl);
    border: 1px solid var(--cs-border);
    min-width: 200px;
    padding: 0.375rem;
    z-index: 50;
    display: none;
}

.cs-dropdown-menu.cs-open {
    display: block;
}

.cs-dropdown-item {
    display: block;
    padding: 0.5rem 0.75rem;
    font-size: 0.9375rem;
    color: var(--cs-text);
    text-decoration: none;
    border-radius: var(--cs-radius-xs);
    transition: background var(--cs-transition);
}

.cs-dropdown-item:hover {
    background: rgba(0, 0, 0, 0.04);
}

.cs-dropdown-divider {
    height: 1px;
    background: var(--cs-border);
    margin: 0.25rem 0;
}

/* ==========================================================================
   Prose / Content
   ========================================================================== */

.cs-prose {
    font-size: 1.0625rem;
    line-height: 1.65;
    color: var(--cs-text);
}

.cs-prose p {
    margin-bottom: 1rem;
}

.cs-prose h2 {
    margin-top: 2rem;
    margin-bottom: 0.75rem;
}

.cs-prose a {
    color: var(--cs-primary);
    text-decoration: underline;
}

.cs-prose ul, .cs-prose ol {
    margin-bottom: 1rem;
    padding-left: 1.5rem;
}

.cs-prose li {
    margin-bottom: 0.25rem;
}

.cs-code {
    font-family: 'SF Mono', 'Menlo', monospace;
    background: rgba(0, 0, 0, 0.04);
    padding: 0.125rem 0.375rem;
    border-radius: 4px;
    font-size: 0.875em;
}

/* Video embeds */
.cs-video-embed {
    position: relative;
    width: 100%;
    padding-top: 56.25%;
    border-radius: var(--cs-radius);
    overflow: hidden;
    background: #000;
}

.cs-video-embed iframe,
.cs-video-embed__native {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* Search */
.cs-search-bar {
    position: relative;
}

.cs-search-bar .cs-form__input,
.cs-search-bar .cs-input {
    padding-left: 2.5rem;
}

/* Language switcher */
.cs-lang-switcher {
    position: relative;
}

.cs-lang-switcher__toggle {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    background: none;
    border: none;
    padding: 0.375rem 0.5rem;
    border-radius: var(--cs-radius-sm);
    cursor: pointer;
    font-size: 0.875rem;
    color: var(--cs-text-secondary);
    transition: background var(--cs-transition);
}

.cs-lang-switcher__toggle:hover {
    background: rgba(0, 0, 0, 0.04);
}

.cs-lang-switcher__menu {
    position: absolute;
    top: calc(100% + 4px);
    right: 0;
    background: var(--cs-surface);
    border-radius: var(--cs-radius);
    box-shadow: var(--cs-shadow-xl);
    border: 1px solid var(--cs-border);
    min-width: 160px;
    padding: 0.375rem;
    z-index: 50;
    display: none;
}

.cs-lang-switcher__menu.cs-open {
    display: block;
}

.cs-lang-switcher__item {
    display: block;
    padding: 0.375rem 0.75rem;
    font-size: 0.875rem;
    color: var(--cs-text);
    text-decoration: none;
    border-radius: var(--cs-radius-xs);
    transition: background var(--cs-transition);
}

.cs-lang-switcher__item:hover {
    background: rgba(0, 0, 0, 0.04);
}

.cs-lang-switcher__item--active {
    color: var(--cs-primary);
    font-weight: 500;
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */

.cs-text-center { text-align: center; }
.cs-text-right { text-align: right; }
.cs-text-muted { color: var(--cs-text-secondary); }
.cs-text-small { font-size: 0.8125rem; }
.cs-text-primary { color: var(--cs-primary); }
.cs-text-success { color: var(--cs-success); }
.cs-text-danger { color: var(--cs-danger); }
.cs-text-warning { color: var(--cs-warning); }

.cs-mt-0 { margin-top: 0; }
.cs-mt-1 { margin-top: 0.5rem; }
.cs-mt-2 { margin-top: 1rem; }
.cs-mt-3 { margin-top: 1.5rem; }
.cs-mt-4 { margin-top: 2rem; }
.cs-mb-0 { margin-bottom: 0; }
.cs-mb-1 { margin-bottom: 0.5rem; }
.cs-mb-2 { margin-bottom: 1rem; }
.cs-mb-3 { margin-bottom: 1.5rem; }
.cs-mb-4 { margin-bottom: 2rem; }

.cs-flex { display: flex; }
.cs-flex-between {
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.cs-flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
}
.cs-gap-1 { gap: 0.5rem; }
.cs-gap-2 { gap: 1rem; }
.cs-gap-3 { gap: 1.5rem; }

.cs-hidden { display: none !important; }

.cs-truncate {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.cs-divider {
    height: 1px;
    background: var(--cs-border);
    margin: 1.5rem 0;
    border: none;
}

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 768px) {
    :root {
        --cs-nav-height: 48px;
    }

    .cs-nav-toggle,
    .cs-header__nav-toggle {
        display: flex;
    }

    .cs-header__nav {
        display: none;
        position: absolute;
        top: var(--cs-nav-height);
        left: 0;
        right: 0;
        background: rgba(251, 251, 253, 0.97);
        -webkit-backdrop-filter: saturate(180%) blur(20px);
        backdrop-filter: saturate(180%) blur(20px);
        flex-direction: column;
        padding: 0.75rem;
        border-bottom: 1px solid var(--cs-border);
    }

    .cs-header__nav.cs-nav-open {
        display: flex;
    }

    .cs-header__nav-link {
        padding: 0.625rem 0.875rem;
        width: 100%;
        border-radius: var(--cs-radius-sm);
    }

    .cs-course-grid,
    .cs-course-grid--2col,
    .cs-course-grid--3col,
    .cs-grid,
    .cs-grid-2,
    .cs-grid-3,
    .cs-grid-4 {
        grid-template-columns: 1fr;
    }

    .cs-stats-row {
        grid-template-columns: repeat(2, 1fr);
    }

    .cs-form__row,
    .cs-form-row {
        flex-direction: column;
        gap: 0;
    }

    .cs-auth-card {
        padding: 1.75rem;
        border-radius: var(--cs-radius-lg);
    }

    .cs-page-header h1,
    .cs-dashboard__title,
    .cs-courses__title {
        font-size: 1.5rem;
    }

    .cs-enrollment-card {
        flex-direction: column;
        text-align: center;
    }

    .cs-layout-sidebar {
        flex-direction: column;
    }

    .cs-sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--cs-border);
        padding: 0.75rem 0;
    }

    .cs-sidebar-content {
        padding: 1rem;
    }

    .cs-footer .cs-container,
    .cs-footer__inner {
        flex-direction: column;
        text-align: center;
    }

    .cs-table-wrapper {
        margin: 0 -1rem;
        border-radius: 0;
        border-left: none;
        border-right: none;
    }

    .cs-detail-grid {
        grid-template-columns: 1fr;
    }

    .cs-breadcrumb {
        font-size: 0.75rem;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .cs-course-grid--3col,
    .cs-grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }

    .cs-grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }

    .cs-stats-row {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ==========================================================================
   Print
   ========================================================================== */

@media print {
    .cs-header,
    .cs-footer,
    .cs-sidebar,
    .cs-nav-toggle {
        display: none !important;
    }

    .cs-main {
        background: #fff;
    }

    .cs-card,
    .cs-course-card,
    .cs-stat-card {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ddd;
    }
}