/**
 * MUSCLAWI DESIGN SYSTEM v1.0
 * Consistent spacing, buttons, cards, and hierarchy across all pages
 * Mobile-first, accessible, minimal visual clutter
 */

:root {
    /* SPACING SCALE (8px base) */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;
    --spacing-xl: 20px;
    --spacing-xxl: 24px;
    --spacing-xxxl: 32px;

    /* TYPOGRAPHY */
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --line-height-tight: 1.3;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;

    /* COLORS */
    --color-bg-primary: #0d1117;
    --color-bg-secondary: #161b22;
    --color-bg-tertiary: #21262d;
    --color-border: #30363d;
    --color-text-primary: #e6edf3;
    --color-text-secondary: #c9d1d9;
    --color-text-muted: #8b949e;
    --color-accent-cyan: #00d4ff;
    --color-accent-cyan-hover: #00b8e6;
    --color-accent-green: #238636;
    --color-accent-green-hover: #2ea043;
    --color-accent-yellow: #d4a70a;
    --color-accent-yellow-hover: #e0c04f;

    /* SHADOWS */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.2);
    --shadow-md: 0 4px 8px rgba(0,0,0,0.25);
    --shadow-lg: 0 8px 16px rgba(0,0,0,0.3);

    /* BORDERS */
    --border-radius-sm: 6px;
    --border-radius-md: 10px;
    --border-radius-lg: 14px;
    --border-radius-full: 999px;

    /* TOUCH TARGETS */
    --min-tap-target: 44px;

    /* TRANSITIONS */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 200ms ease-in-out;

    /* NAVIGATION */
    --safe-top: env(safe-area-inset-top, 0);
    --safe-bottom: env(safe-area-inset-bottom, 0);
    --safe-left: env(safe-area-inset-left, 0);
    --safe-right: env(safe-area-inset-right, 0);
    --bottom-nav-height: 64px;
}

/* ============================================================================
   GLOBAL STYLES
   ============================================================================ */

html {
    -webkit-text-size-adjust: 100%;
}

body {
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    margin: 0;
    padding: var(--spacing-lg);
    padding-left: calc(var(--spacing-lg) + var(--safe-left));
    padding-right: calc(var(--spacing-lg) + var(--safe-right));
    padding-bottom: calc(var(--spacing-lg) + var(--safe-bottom));
    line-height: var(--line-height-normal);
    font-size: var(--font-size-base);
}

@media (min-width: 769px) {
    body {
        padding: var(--spacing-xl);
        padding-left: calc(var(--spacing-xl) + var(--safe-left));
        padding-right: calc(var(--spacing-xl) + var(--safe-right));
        padding-bottom: calc(var(--spacing-xl) + var(--safe-bottom));
    }
}

/* ============================================================================
   BUTTONS - UNIFIED SYSTEM
   ============================================================================ */

button,
.btn,
.btn-header,
a.btn-header {
    -webkit-tap-highlight-color: rgba(0, 212, 255, 0.2);
    touch-action: manipulation;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    min-height: var(--min-tap-target);
    padding: var(--spacing-md) var(--spacing-lg);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    background-color: var(--color-bg-tertiary);
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

button:hover,
.btn:hover,
.btn-header:hover {
    background-color: var(--color-border);
    color: var(--color-text-primary);
    border-color: var(--color-accent-cyan);
}

button:active,
.btn:active,
.btn-header:active {
    opacity: 0.9;
    transform: scale(0.96);
}

/* UPGRADE-1: Micro-interactions for premium feel */
button:not(:disabled),
.btn:not(:disabled),
.btn-header:not(:disabled) {
    transition: all 80ms cubic-bezier(0.4, 0, 0.2, 1);
}

button:disabled,
.btn:disabled,
.btn-header:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

/* PRIMARY BUTTON (Green) */
.btn-primary,
.btn-header.primary,
button.primary {
    background-color: var(--color-accent-green);
    color: white;
    border-color: var(--color-accent-green);
}

.btn-primary:hover,
.btn-header.primary:hover,
button.primary:hover {
    background-color: var(--color-accent-green-hover);
    border-color: var(--color-accent-green-hover);
    color: white;
}

/* CTA BUTTON (Cyan - Large) */
.btn-cta,
.btn-header.cta,
button.cta {
    background: linear-gradient(135deg, var(--color-accent-cyan), #00aaff);
    color: #0a0a0a;
    border: none;
    font-weight: 700;
    padding: var(--spacing-lg) var(--spacing-xl);
    font-size: var(--font-size-base);
    min-height: 48px;
}

.btn-cta:hover,
.btn-header.cta:hover,
button.cta:hover {
    background: linear-gradient(135deg, var(--color-accent-cyan-hover), #0099cc);
    color: #000;
}

/* SMALL BUTTON */
.btn-sm {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-xs);
    min-height: 32px;
}

/* FULL-WIDTH BUTTON */
.btn-block {
    width: 100%;
}

/* ============================================================================
   HERO SECTION - Clean, centered, consistent spacing
   ============================================================================ */

.header {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    margin-bottom: var(--spacing-xxxl);
    gap: var(--spacing-md);
}

.header-brand {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

.brand-logo {
    height: clamp(80px, 15vw, 120px);
    width: auto;
    object-fit: contain;
    display: block;
}

.header .tagline {
    font-size: clamp(1.125rem, 2.5vw, 1.5rem);
    color: var(--color-text-primary);
    margin: 0;
    font-weight: 700;
    letter-spacing: 0.03em;
    line-height: var(--line-height-tight);
}

.status-pill {
    background-color: var(--color-bg-tertiary);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius-full);
    font-size: var(--font-size-sm);
    color: var(--color-accent-cyan);
    border: 1px solid var(--color-border);
    font-weight: 500;
}

/* Header button group - responsive grid */
.header-actions {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    width: 100%;
    margin-top: var(--spacing-lg);
}

@media (min-width: 480px) {
    .header-actions {
        flex-direction: row;
        justify-content: center;
        flex-wrap: wrap;
        width: auto;
    }

    .header-actions .btn,
    .header-actions .btn-header {
        flex: 0 1 auto;
    }
}

/* ============================================================================
   GUEST BANNER - Single, neat card with consistent spacing
   ============================================================================ */

#guest-banner {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-xxl);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

#guest-banner .icon {
    font-size: var(--font-size-xl);
}

#guest-banner-text {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    margin: 0;
    line-height: var(--line-height-normal);
}

/* ============================================================================
   CARDS - Uniform sizing, padding, hierarchy
   ============================================================================ */

.card {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    transition: all var(--transition-normal);
    display: flex;
    flex-direction: column;
    min-height: 280px;
    position: relative;
    /* UPGRADE-3: Add subtle inner border for glass-like depth */
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background-color: var(--color-accent-cyan);
    border-radius: var(--border-radius-md) 0 0 var(--border-radius-md);
}

/* UPGRADE-3: Card elevation on hover */
.card:hover {
    border-color: var(--color-accent-cyan);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04), 0 6px 16px rgba(0, 212, 255, 0.12);
    transform: translateY(-2px);
}

.card h3 {
    font-size: clamp(var(--font-size-base), 2vw, var(--font-size-lg));
    font-weight: 600;
    color: var(--color-text-primary);
    margin: 0 0 var(--spacing-md) 0;
    line-height: var(--line-height-tight);
}

.card p {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin: 0 0 var(--spacing-md) 0;
    line-height: var(--line-height-normal);
}

.card-stats {
    color: var(--color-text-muted);
    font-size: var(--font-size-xs);
    margin-bottom: var(--spacing-md);
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.card-highlight {
    color: var(--color-accent-cyan);
    font-weight: 600;
}

.card-action {
    margin-top: auto;
}

.card-details-link {
    margin-top: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-border);
    font-size: var(--font-size-sm);
    color: var(--color-accent-cyan);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.card-details-link:hover {
    text-decoration: underline;
    color: var(--color-accent-cyan-hover);
}

/* ============================================================================
   CARDS GRID - Responsive layout
   ============================================================================ */

#workout-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
}

@media (min-width: 640px) {
    #workout-container {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
        gap: var(--spacing-xl);
    }
}

@media (min-width: 1024px) {
    #workout-container {
        grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
        gap: var(--spacing-xxl);
    }
}

/* ============================================================================
   BOTTOM NAVIGATION - Consistent with main UI
   ============================================================================ */

#bottom-nav {
    display: none;
    z-index: 100;
    pointer-events: auto;
}

@media (max-width: 768px) {
    #bottom-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        height: calc(var(--bottom-nav-height) + var(--safe-bottom));
        padding-bottom: var(--safe-bottom);
        background-color: var(--color-bg-secondary);
        border-top: 1px solid var(--color-border);
        box-shadow: 0 -4px 12px rgba(0, 0, 0, 0.3);
        justify-content: space-around;
        align-items: center;
        gap: var(--spacing-xs);
    }

    #bottom-nav .nav-item {
        flex: 1;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: var(--spacing-xs);
        padding: var(--spacing-sm) var(--spacing-xs);
        min-height: 48px;
        color: var(--color-text-muted);
        text-decoration: none;
        transition: all var(--transition-fast);
        font-size: var(--font-size-xs);
        font-weight: 500;
    }

    #bottom-nav .nav-item:hover,
    #bottom-nav .nav-item:focus {
        color: var(--color-accent-yellow);
    }

    #bottom-nav .nav-item.active {
        color: var(--color-accent-yellow);
    }

    #bottom-nav .nav-icon {
        font-size: 1.5rem;
        line-height: 1;
    }
}

/* Adjust main content padding for mobile bottom nav */
@media (max-width: 768px) {
    body {
        padding-bottom: calc(var(--bottom-nav-height) + var(--safe-bottom) + var(--spacing-lg));
    }
}

/* ============================================================================
   MODALS - Consistent sizing and spacing
   ============================================================================ */

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.9);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    padding: var(--spacing-lg);
}

.modal.show {
    display: flex;
}

.modal-content {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    width: 100%;
    max-width: 500px;
    max-height: calc(100vh - var(--spacing-lg) * 2);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    /* UPGRADE-3: Glass-like depth effect */
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.06), 0 8px 32px rgba(0, 0, 0, 0.4);
}

@media (max-width: 768px) {
    .modal-content {
        max-height: calc(100vh - var(--bottom-nav-height) - var(--spacing-lg) * 2 - var(--safe-bottom));
        padding-bottom: calc(var(--spacing-xl) + var(--bottom-nav-height));
    }
}

.modal-content h2 {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-accent-cyan);
    margin: 0 0 var(--spacing-lg) 0;
}

.modal-content h3 {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-text-primary);
    margin: var(--spacing-lg) 0 var(--spacing-md) 0;
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    font-weight: 500;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    color: var(--color-text-primary);
    font-size: var(--font-size-base);
    font-family: inherit;
    transition: all var(--transition-fast);
    box-sizing: border-box;
    min-height: var(--min-tap-target);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-accent-cyan);
    background-color: var(--color-bg-tertiary);
    /* UPGRADE-1: Smooth cyan glow on focus */
    box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.15), inset 0 0 8px rgba(0, 212, 255, 0.05);
    transition: box-shadow 150ms ease, border-color 150ms ease;
}

/* UPGRADE-1: Success state for inputs (green border after blur with value) */
.form-group input:not(:focus):valid {
    border-color: var(--color-accent-green);
    box-shadow: inset 0 0 8px rgba(46, 125, 50, 0.05);
}

/* ============================================================================
   UPGRADE-1: ANIMATIONS & KEYFRAMES
   ============================================================================ */

@keyframes ripple {
    0% {
        box-shadow: 0 0 0 0 rgba(0, 212, 255, 0.7);
    }
    70% {
        box-shadow: 0 0 0 12px rgba(0, 212, 255, 0);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(0, 212, 255, 0);
    }
}

@keyframes slideUpFade {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideDownFade {
    from {
        opacity: 1;
        transform: translateY(0);
    }
    to {
        opacity: 0;
        transform: translateY(16px);
    }
}

@keyframes pulse-3x {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

@keyframes glow-cyan {
    0%, 100% {
        box-shadow: 0 0 0 0 rgba(0, 212, 255, 0.2), inset 0 0 8px rgba(0, 212, 255, 0.1);
    }
    50% {
        box-shadow: 0 0 0 4px rgba(0, 212, 255, 0.1), inset 0 0 8px rgba(0, 212, 255, 0.15);
    }
}

@keyframes shimmer {
    0% {
        background-position: -1000px 0;
    }
    100% {
        background-position: 1000px 0;
    }
}

@keyframes slide-left {
    from { opacity: 1; transform: translateX(0); }
    to { opacity: 0; transform: translateX(-100%); }
}

@keyframes slide-right {
    from { opacity: 0; transform: translateX(100%); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes typing-dots {
    0%, 60%, 100% { opacity: 0.3; transform: translateY(0); }
    30% { opacity: 1; transform: translateY(-8px); }
}

/* ============================================================================
   UTILITY CLASSES
   ============================================================================ */

/* ============================================================================
   UPGRADE-4: LOADING STATES & SKELETONS
   ============================================================================ */

.skeleton {
    background: linear-gradient(
        90deg,
        var(--color-bg-tertiary) 0%,
        var(--color-border) 50%,
        var(--color-bg-tertiary) 100%
    );
    background-size: 200% 100%;
    animation: shimmer 2s infinite;
    border-radius: var(--border-radius-sm);
}

.skeleton-row {
    height: 40px;
    margin-bottom: var(--spacing-sm);
    border-radius: var(--border-radius-sm);
}

.typing-dots {
    display: inline-flex;
    gap: 4px;
}

.typing-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--color-accent-cyan);
}

.typing-dot:nth-child(1) {
    animation: typing-dots 1.2s infinite 0ms;
}

.typing-dot:nth-child(2) {
    animation: typing-dots 1.2s infinite 200ms;
}

.typing-dot:nth-child(3) {
    animation: typing-dots 1.2s infinite 400ms;
}

.text-center {
    text-align: center;
}

.text-muted {
    color: var(--color-text-muted);
}

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-row { flex-direction: row; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }

/* ============================================================================
   RTL SUPPORT
   ============================================================================ */

[dir="rtl"] .header {
    text-align: right;
}

[dir="rtl"] .form-group {
    text-align: right;
}

[dir="rtl"] .card::before {
    left: auto;
    right: 0;
    border-radius: 0 var(--border-radius-md) var(--border-radius-md) 0;
}

/* ============================================================================
   ACCESSIBILITY
   ============================================================================ */

@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
button:focus-visible,
.btn:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible {
    outline: 2px solid var(--color-accent-cyan);
    outline-offset: 2px;
}

/* ============================================================================
   UPGRADE-5: SECTION TRANSITIONS & NAVIGATION FEEL
   ============================================================================ */

.spa-section {
    animation: slideInFromRight 200ms ease-out;
}

@keyframes slideInFromRight {
    from {
        opacity: 0;
        transform: translateX(20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* UPGRADE-5: Animated bottom nav indicator */
@media (max-width: 768px) {
    #bottom-nav .nav-item {
        position: relative;
    }

    #bottom-nav .nav-item::after {
        content: '';
        position: absolute;
        bottom: -1px;
        left: 50%;
        transform: translateX(-50%);
        width: 0;
        height: 3px;
        background-color: var(--color-accent-yellow);
        border-radius: 3px 3px 0 0;
        transition: width 200ms cubic-bezier(0.4, 0, 0.2, 1);
    }

    #bottom-nav .nav-item.active::after {
        width: 24px;
    }
}

/* ============================================================================
   PRINT STYLES
   ============================================================================ */

@media print {
    #bottom-nav,
    .modal {
        display: none !important;
    }
}