/*
 * =============================================
 * KAVI G — Design System CSS
 * =============================================
 * Table of Contents:
 *
 * 1. Design Tokens (Custom Properties)
 * 2. Reduced Motion Override
 * 3. Base Styles (body, skip-to-content)
 * 4. Typography Utilities
 * 5. Responsive Typography
 * 6. Dividers
 * 7. Image Treatment Filters
 * 8. Button Styles
 * 9. Focus Ring
 * 10. Cultural SVG Utilities
 * 11. Color Utilities
 * 12. Navigation
 * 13. Error Pages
 * 14. Scroll Reveal Animations
 * 15. Skeleton/Shimmer Loading
 * 16. Button State Extensions
 * 17. Card Hover & Extended Focus Rings
 * 18. Counter & Countdown Animations
 * 19. Text Stagger, Cursor Glow & Vinyl Spin
 * =============================================
 */

/*
 * TOKEN ENFORCEMENT RULE:
 * All color values MUST use var(--color-*) semantic tokens.
 * Raw hex/rgb values are ONLY permitted in:
 *   - :root {} token definitions
 *   - CSS gradients (browser compatibility)
 *   - CSS box-shadow rgba() values (browser compatibility)
 * New CSS that violates this rule should be flagged in code review.
 */

/* 1. Design Tokens (Custom Properties) */
:root {
    /* Surface scale (4-tier) */
    --color-surface-0: #0A0A0A;
    --color-surface-1: #141414;
    --color-surface-2: #1E1E1E;
    --color-surface-3: #2A2A2A;

    /* Gold accent */
    --color-primary: #FFD700;
    --color-primary-dark: #B8860B;
    --gradient-gold: linear-gradient(135deg, #FFD700, #B8860B);

    /* Cultural accent */
    --color-crimson: #DC143C;
    --color-error: #DC143C;

    /* Text */
    --color-on-surface: #FFFFFF;
    --color-on-surface-muted: #B0B0B0;
    --color-on-primary: #0A0A0A;

    /* Dividers */
    --color-divider: rgba(255, 215, 0, 0.2);

    /* Typography */
    --font-display: 'Anton', sans-serif;
    --font-body: 'Space Grotesk', sans-serif;
    --font-accent: 'Rajdhani', sans-serif;

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;

    /* Layout */
    --nav-height: 72px;
    --max-content-width: 1440px;

    /* Z-index */
    --z-nav: 100;
    --z-overlay: 200;
    --z-modal: 300;
    --z-toast: 400;

    /* Motion */
    --duration-fast: 300ms;
    --duration-default: 600ms;
    --duration-slow: 900ms;
    --easing-default: ease-out;
}

/* 2. Reduced Motion Override */
@media (prefers-reduced-motion: reduce) {
    :root {
        --duration-fast: 0ms;
        --duration-default: 0ms;
        --duration-slow: 0ms;
    }
}

/* 3. Base Styles */
html {
    overflow-x: hidden;
}

body {
    background-color: var(--color-surface-0);
    color: var(--color-on-surface-muted);
    font-family: var(--font-body);
    padding-top: var(--nav-height);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

#main-content {
    flex: 1 0 auto;
}

.site-footer {
    flex-shrink: 0;
}

/* Skip to content — hidden until focused (WCAG 2.4.1) */
.skip-to-content {
    position: absolute;
    left: -9999px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
    z-index: calc(var(--z-toast) + 100);
}

.skip-to-content:focus {
    position: fixed;
    left: 50%;
    top: var(--space-sm);
    transform: translateX(-50%);
    width: auto;
    height: auto;
    overflow: visible;
    background: var(--color-primary);
    color: var(--color-on-primary);
    font-family: var(--font-accent);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: var(--space-sm) var(--space-lg);
    text-decoration: none;
    outline: 2px solid var(--color-on-surface);
    outline-offset: 2px;
}

/* Hero sections go full-bleed under transparent nav */
.hero-section {
    margin-top: calc(-1 * var(--nav-height));
    padding-top: var(--nav-height);
}

/* 4. Typography Utilities */
.font-display { font-family: var(--font-display); text-transform: uppercase; }
.font-body { font-family: var(--font-body); }
.font-accent { font-family: var(--font-accent); }

.heading-display {
    font-family: var(--font-display);
    font-size: 48px;
    font-weight: 400;
    line-height: 1.1;
    text-transform: uppercase;
    color: var(--color-on-surface);
}

.heading-section {
    font-family: var(--font-display);
    font-size: 28px;
    font-weight: 400;
    line-height: 1.2;
    text-transform: uppercase;
    color: var(--color-on-surface);
}

.heading-subsection {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 400;
    line-height: 1.3;
    text-transform: uppercase;
    color: var(--color-on-surface);
}

.text-accent {
    font-family: var(--font-accent);
    font-size: 14px;
    font-weight: 500;
    line-height: 1.3;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.text-label {
    font-family: var(--font-accent);
    font-size: 12px;
    font-weight: 500;
    line-height: 1.4;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-on-surface-muted);
}

/* 5. Responsive Typography */
@media (max-width: 575px) {
    .heading-display { font-size: 32px; }
    .heading-section { font-size: 22px; }
    .heading-subsection { font-size: 18px; }
}
@media (min-width: 576px) and (max-width: 991px) {
    .heading-display { font-size: 40px; }
    .heading-section { font-size: 26px; }
    .heading-subsection { font-size: 19px; }
}

/* 6. Dividers */
.divider-gold {
    border: none;
    border-top: 1px solid var(--color-divider);
    margin: var(--space-2xl) 0;
}

/* 7. Image Treatment Filters */
.img-gold-duotone {
    filter: sepia(100%) saturate(300%) brightness(70%) hue-rotate(10deg);
}

.img-bw-contrast {
    filter: grayscale(100%) contrast(1.2) brightness(0.8);
}

.img-gold-overlay {
    position: relative;
    overflow: hidden;
}
.img-gold-overlay img {
    filter: grayscale(100%) contrast(1.2) brightness(0.8);
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.img-gold-overlay::after {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-gold);
    opacity: 0.2;
    mix-blend-mode: overlay;
    pointer-events: none;
}

/* 8. Button Styles */
.btn-gold {
    display: inline-block;
    padding: var(--space-sm) var(--space-lg);
    background: var(--gradient-gold);
    color: var(--color-on-primary);
    font-family: var(--font-accent);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border: none;
    border-radius: 0;
    text-decoration: none;
    transition: opacity var(--duration-fast) var(--easing-default),
                transform var(--duration-fast) var(--easing-default);
}
.btn-gold:hover {
    opacity: 0.9;
    color: var(--color-on-primary);
    text-decoration: none;
}
.btn-gold:active {
    transform: scale(0.97);
}

.btn-gold-outline {
    display: inline-block;
    padding: var(--space-sm) var(--space-lg);
    background: transparent;
    color: var(--color-primary);
    font-family: var(--font-accent);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border: 1px solid var(--color-primary);
    border-radius: 0;
    text-decoration: none;
    transition: background-color var(--duration-fast) var(--easing-default),
                color var(--duration-fast) var(--easing-default);
}
.btn-gold-outline:hover,
.btn-gold-outline.active {
    background-color: var(--color-primary);
    color: var(--color-on-primary);
    text-decoration: none;
}
.btn-gold-outline:active {
    transform: scale(0.97);
}

/* 9. Focus Ring */
:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* 10. Cultural SVG Utilities */
.dhaka-bg {
    position: relative;
}
.dhaka-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image: url('/svg/dhaka-pattern.svg');
    background-repeat: repeat;
    background-size: 120px;
    opacity: 0.06;
    pointer-events: none;
    z-index: 0;
}
.dhaka-bg > * {
    position: relative;
    z-index: 1;
}

/* 11. Color Utilities */
.text-gold { color: var(--color-primary); }
.text-crimson { color: var(--color-crimson); }
.text-muted-custom { color: var(--color-on-surface-muted); }
.bg-surface-0 { background-color: var(--color-surface-0); }
.bg-surface-1 { background-color: var(--color-surface-1); }
.bg-surface-2 { background-color: var(--color-surface-2); }
.bg-surface-3 { background-color: var(--color-surface-3); }

/* =============================================
 * 12. Navigation
 * ============================================= */

.navbar-kavig {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: var(--z-nav);
    background-color: transparent;
    transition: background-color var(--duration-fast) var(--easing-default),
                backdrop-filter var(--duration-fast) var(--easing-default);
    height: var(--nav-height);
    padding-top: 0;
    padding-bottom: 0;
}

.navbar-kavig.nav-scrolled {
    background-color: rgba(20, 20, 20, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

/* Non-hero pages: nav starts solid immediately */
.navbar-kavig.nav-solid {
    background-color: rgba(20, 20, 20, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.navbar-kavig .navbar-brand {
    color: var(--color-primary);
    font-size: 1.5rem;
    letter-spacing: 0.05em;
}

.navbar-kavig .nav-link {
    color: var(--color-on-surface);
    font-family: var(--font-accent);
    font-weight: 500;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: var(--space-sm) var(--space-md);
    position: relative;
    transition: color var(--duration-fast) var(--easing-default);
}

/* Gold underline - active state */
.navbar-kavig .nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: var(--space-md);
    right: var(--space-md);
    height: 2px;
    background-color: var(--color-primary);
}

/* Gold underline - hover animation (slides from left) */
.navbar-kavig .nav-link:not(.active)::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: var(--space-md);
    right: var(--space-md);
    height: 2px;
    background-color: var(--color-primary);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--duration-fast) var(--easing-default);
}

.navbar-kavig .nav-link:not(.active):hover::after {
    transform: scaleX(1);
}

.navbar-kavig .nav-link:hover {
    color: var(--color-primary);
}

/* Dropdown styling */
.dropdown-menu-kavig {
    background-color: var(--color-surface-2);
    border: 1px solid var(--color-divider);
    border-radius: 0;
    padding: var(--space-xs) 0;
}

.dropdown-menu-kavig .dropdown-item {
    color: var(--color-on-surface);
    font-family: var(--font-accent);
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: var(--space-sm) var(--space-md);
    transition: background-color var(--duration-fast) var(--easing-default),
                color var(--duration-fast) var(--easing-default);
}

.dropdown-menu-kavig .dropdown-item:hover {
    background-color: var(--color-surface-3);
    color: var(--color-primary);
}

/* Dropdown chevron rotation */
.navbar-kavig .dropdown-toggle::after {
    transition: transform var(--duration-fast) var(--easing-default);
}

.navbar-kavig .dropdown-toggle[aria-expanded="true"]::after {
    transform: rotate(180deg);
}

/* Nav CTA button */
.btn-nav-cta {
    font-size: 13px;
    padding: var(--space-xs) var(--space-md);
}

/* Custom hamburger with gold bars */
.navbar-toggler-kavig {
    border: 1px solid var(--color-primary);
    padding: var(--space-xs) var(--space-sm);
    position: relative;
    width: 44px;
    height: 44px;
}

.navbar-toggler-kavig:focus {
    box-shadow: 0 0 0 2px var(--color-primary);
}

.navbar-toggler-kavig .toggler-bar {
    display: block;
    width: 22px;
    height: 2px;
    background-color: var(--color-primary);
    margin: 4px auto;
    transition: transform var(--duration-fast) var(--easing-default),
                opacity var(--duration-fast) var(--easing-default);
}

/* Hamburger → X animation on open */
.navbar-toggler-kavig[aria-expanded="true"] .toggler-bar:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}

.navbar-toggler-kavig[aria-expanded="true"] .toggler-bar:nth-child(2) {
    opacity: 0;
}

.navbar-toggler-kavig[aria-expanded="true"] .toggler-bar:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

/* Mobile nav overlay */
@media (max-width: 991px) {
    .navbar-kavig .navbar-collapse {
        background-color: var(--color-surface-0);
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        bottom: 0;
        padding: var(--space-xl);
        overflow-y: auto;
    }

    /* 44px minimum touch target */
    .navbar-kavig .nav-link {
        font-size: 18px;
        padding: 13px 0;
        min-height: 44px;
        display: flex;
        align-items: center;
        border-bottom: 1px solid var(--color-divider);
    }

    .navbar-kavig .btn-nav-cta {
        margin-top: var(--space-lg);
        display: flex;
        text-align: center;
        min-height: 44px;
        align-items: center;
        justify-content: center;
    }

    .dropdown-menu-kavig {
        background-color: transparent;
        border: none;
        padding-left: var(--space-lg);
    }

    .dropdown-menu-kavig .dropdown-item {
        min-height: 44px;
        display: flex;
        align-items: center;
    }
}

/* =============================================
 * 13. Error Pages
 * ============================================= */

.error-page {
    padding: var(--space-3xl) var(--space-lg);
}

.error-svg {
    width: 200px;
    max-width: 80vw;
    height: auto;
    opacity: 0.4;
    animation: errorFadeIn var(--duration-slow) var(--easing-default) forwards;
}

@keyframes errorFadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 0.4;
        transform: translateY(0);
    }
}

/* =============================================
 * 14. Scroll Reveal Animations
 * ============================================= */

/* Container: applied to sections that reveal on scroll */
.reveal-on-scroll {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity var(--duration-default) var(--easing-default),
                transform var(--duration-default) var(--easing-default);
}

.reveal-on-scroll.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* Children: stagger-animated items within a reveal container */
.reveal-item {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity var(--duration-default) var(--easing-default),
                transform var(--duration-default) var(--easing-default);
}

.reveal-on-scroll.revealed .reveal-item {
    opacity: 1;
    transform: translateY(0);
}

/* =============================================
 * 15. Skeleton/Shimmer Loading
 * ============================================= */

.skeleton {
    background-color: var(--color-surface-1);
    position: relative;
    overflow: hidden;
    border-radius: 4px;
}

.skeleton::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(
        90deg,
        transparent 0%,
        rgba(30, 30, 30, 0.8) 40%,
        rgba(255, 215, 0, 0.05) 50%,
        rgba(30, 30, 30, 0.8) 60%,
        transparent 100%
    );
    transform: translateX(-100%);
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    100% {
        transform: translateX(100%);
    }
}

/* Skeleton shape variants */
.skeleton-text {
    height: 12px;
    border-radius: 6px;
    margin-bottom: var(--space-sm);
}

.skeleton-text:last-child {
    width: 60%;
}

.skeleton-image {
    width: 100%;
    aspect-ratio: 16 / 9;
}

.skeleton-card {
    padding: var(--space-md);
}

.skeleton-card .skeleton-image {
    margin-bottom: var(--space-md);
}

/* =============================================
 * 16. Button State Extensions (disabled, loading)
 * ============================================= */

/* Disabled state */
.btn-gold[disabled],
.btn-gold.disabled,
.btn-gold-outline[disabled],
.btn-gold-outline.disabled {
    opacity: 0.4;
    pointer-events: none;
    cursor: not-allowed;
}

/* Loading state */
.btn-loading {
    position: relative;
    color: transparent !important;
    pointer-events: none;
    min-width: var(--btn-min-width, auto);
}

.btn-loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 16px;
    height: 16px;
    margin-top: -8px;
    margin-left: -8px;
    border: 2px solid transparent;
    border-top-color: var(--color-primary);
    border-right-color: var(--color-primary);
    border-radius: 50%;
    animation: btnSpin var(--duration-default) linear infinite;
}

@keyframes btnSpin {
    to {
        transform: rotate(360deg);
    }
}

/* =============================================
 * 17. Card Hover & Extended Focus Rings
 * ============================================= */

/* Card component base */
.card-kavig {
    background-color: var(--color-surface-1);
    border: 1px solid transparent;
    overflow: hidden;
    transition: box-shadow var(--duration-fast) var(--easing-default),
                border-color var(--duration-fast) var(--easing-default);
}

.card-kavig:hover {
    box-shadow: 0 0 0 1px var(--color-primary),
                0 0 20px rgba(255, 215, 0, 0.15);
}

.card-kavig .card-kavig-image {
    overflow: hidden;
}

.card-kavig .card-kavig-image img {
    transition: transform var(--duration-fast) var(--easing-default);
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.card-kavig:hover .card-kavig-image img {
    transform: scale(1.03);
}

/* Extended focus rings — larger interactive elements get 3px */
.btn-gold:focus-visible,
.btn-gold-outline:focus-visible {
    outline-width: 3px;
    outline-offset: 3px;
}

.card-kavig:focus-visible {
    outline: none;
    box-shadow: 0 0 0 1px var(--color-primary),
                0 0 20px rgba(255, 215, 0, 0.15);
}

input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline-width: 3px;
    outline-offset: 2px;
}

/* Global touch target enforcement (WCAG 2.5.5) */
.btn-gold,
.btn-gold-outline,
.card-kavig a,
.card-kavig button,
button,
input[type="submit"],
input[type="button"],
input[type="reset"],
select,
[role="button"] {
    min-height: 44px;
}

/* Touch target spacing utility */
.touch-gap {
    gap: var(--space-sm);
}

/* =============================================
 * 18. Counter & Countdown Animations
 * ============================================= */

/* Countdown flip container */
.countdown-digit {
    display: inline-block;
    perspective: 300px;
    overflow: hidden;
}

.countdown-digit .digit-inner {
    display: inline-block;
    transition: transform var(--duration-fast) var(--easing-default);
    font-variant-numeric: tabular-nums;
}

.countdown-digit .digit-inner.flipping {
    transform: rotateX(-90deg);
}

/* =============================================
 * 19. Text Stagger, Cursor Glow & Vinyl Spin
 * ============================================= */

/* Text stagger — word-by-word reveal */
.stagger-word {
    display: inline-block;
    opacity: 0;
    transform: translateY(100%);
    transition: opacity var(--duration-default) var(--easing-default),
                transform var(--duration-default) var(--easing-default);
}

.stagger-word.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* Cursor glow — hero section, desktop only */
@media (hover: hover) {
    .hero-section {
        --mouse-x: 50%;
        --mouse-y: 50%;
    }

    .hero-section::before {
        content: '';
        position: absolute;
        inset: 0;
        background: radial-gradient(
            300px circle at var(--mouse-x) var(--mouse-y),
            rgba(255, 215, 0, 0.06),
            transparent 70%
        );
        pointer-events: none;
        z-index: 1;
    }
}

/* Vinyl spin — album cover hover */
.vinyl-hover {
    position: relative;
    transition: box-shadow var(--duration-fast) var(--easing-default);
}

.vinyl-hover img {
    transition: transform 0s linear;
}

.vinyl-hover:hover img {
    animation: vinylSpin 4s linear infinite;
}

.vinyl-hover:not(:hover) img {
    animation-play-state: paused;
}

/* Vinyl center shadow */
.vinyl-hover::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 30%;
    height: 30%;
    transform: translate(-50%, -50%);
    border-radius: 50%;
    box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.6);
    pointer-events: none;
    z-index: 2;
}

@keyframes vinylSpin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* =============================================
 * 20. Phase 3 Reduced Motion Overrides
 * ============================================= */

@media (prefers-reduced-motion: reduce) {
    /* Skeleton shimmer — static placeholder */
    .skeleton::after {
        animation: none;
    }

    /* Button spinner — static indicator */
    .btn-loading::after {
        animation: none;
        border-color: var(--color-primary);
        opacity: 0.6;
    }

    /* Card hover — glow only, no zoom */
    .card-kavig .card-kavig-image img {
        transition: none;
    }

    .card-kavig:hover .card-kavig-image img {
        transform: none;
    }

    /* Text stagger — instant reveal */
    .stagger-word {
        opacity: 1;
        transform: none;
        transition: none;
    }

    /* Vinyl spin — static only */
    .vinyl-hover:hover img {
        animation: none;
    }

    /* Cursor glow — disabled */
    @media (hover: hover) {
        .hero-section::before {
            display: none;
        }
    }
}

/* =============================================
 * 22. Footer
 * ============================================= */

.footer-social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    font-size: 1.25rem;
    color: var(--color-on-surface-muted);
    border: 1px solid var(--color-divider);
    transition: color var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
    text-decoration: none;
}

.footer-social-link:hover,
.footer-social-link:focus-visible {
    color: var(--color-primary);
    border-color: var(--color-primary);
    transform: translateY(-2px);
}

.footer-nav-link {
    color: var(--color-on-surface-muted);
    text-decoration: none;
    font-family: var(--font-accent);
    font-size: 0.8125rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    transition: color var(--transition-fast);
}

.footer-nav-link:hover,
.footer-nav-link:focus-visible {
    color: var(--color-primary);
}