/* ============================================
   CSS RESET & BASE STYLES
   ============================================ */

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* ============================================
   CSS VARIABLES
   ============================================ */

:root {
  /* Theme colors - will be set dynamically by JavaScript */
  --color-primary: #D4AF37;
  --color-secondary: #2C3E50;
  --color-accent: #E8B4B8;
  --color-background: #FEFEFE;
  --color-text: #1A1A1A;
  --color-text-light: #6B7280;
  --color-error: #DC2626;

  /* Fonts - will be set dynamically */
  --font-heading: 'Playfair Display', serif;
  --font-body: 'Inter', sans-serif;

  /* Animation durations */
  --duration-fast: 0.2s;
  --duration-normal: 0.4s;
  --duration-slow: 0.8s;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;

  /* Border radius */
  --radius-sm: 0.5rem;
  --radius-md: 1rem;
  --radius-lg: 2rem;
  --radius-full: 9999px;
}

/* ============================================
   BASE STYLES
   ============================================ */

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    color: var(--color-text);
    background:
        radial-gradient(circle at 20% 20%, rgba(212, 175, 55, 0.2), transparent 40%),
        radial-gradient(circle at 85% 15%, rgba(232, 180, 184, 0.2), transparent 35%),
        linear-gradient(180deg, #fffaf2 0%, var(--color-background) 45%, #fff7fb 100%);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* ============================================
   MAIN CONTAINER
   ============================================ */

.birthday-card {
    width: min(100%, 760px);
    margin: var(--spacing-md) auto var(--spacing-xl);
    padding: var(--spacing-md);
}

.card-stage {
    perspective: 1800px;
    margin-bottom: var(--spacing-lg);
}

.card-book {
    position: relative;
    border-radius: var(--radius-lg);
    min-height: 780px;
    transform-style: preserve-3d;
    box-shadow:
        0 24px 40px rgba(44, 62, 80, 0.18),
        0 0 0 1px rgba(255, 255, 255, 0.65) inset;
}

.card-cover {
    position: absolute;
    inset: 0;
    z-index: 3;
    border: 0;
    border-radius: var(--radius-lg);
    transform-origin: left center;
    transform-style: preserve-3d;
    transform: rotateY(0deg);
    transition: transform 7000ms cubic-bezier(0.14, 0.84, 0.18, 1);
    cursor: pointer;
    color: var(--color-background);
    background:
        linear-gradient(145deg, rgba(255, 255, 255, 0.18), transparent 50%),
        linear-gradient(135deg, var(--color-secondary), var(--color-primary));
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    overflow: hidden;
    backface-visibility: hidden;
}

.card-cover::before {
    content: "";
    position: absolute;
    inset: 14px;
    border-radius: calc(var(--radius-lg) - 8px);
    border: 1px solid rgba(255, 255, 255, 0.4);
    pointer-events: none;
}

.cover-title {
    font-family: var(--font-heading);
    font-size: clamp(2rem, 5vw, 3rem);
    letter-spacing: 0.04em;
    text-transform: uppercase;
    text-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

.cover-subtitle {
    font-family: var(--font-heading);
    font-size: clamp(1.3rem, 3vw, 1.9rem);
    font-weight: 600;
    opacity: 0.95;
}

.cover-hint {
    font-size: 0.95rem;
    padding: 0.25rem 0.9rem;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.18);
    border: 1px solid rgba(255, 255, 255, 0.3);
    transition: opacity 260ms ease;
}

.card-book.is-open .card-cover {
    transform: rotateY(-165deg);
    pointer-events: none;
}

.card-book.is-open .cover-hint {
    opacity: 0;
}

.card-actions {
    text-align: center;
    margin-top: var(--spacing-md);
}

.card-toggle-button {
    border: 0;
    border-radius: var(--radius-full);
    background: var(--color-secondary);
    color: #fff;
    padding: 0.65rem 1.4rem;
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: transform var(--duration-fast) ease, box-shadow var(--duration-fast) ease;
    box-shadow: 0 8px 16px rgba(44, 62, 80, 0.22);
}

.card-toggle-button:hover {
    transform: translateY(-1px);
    box-shadow: 0 10px 20px rgba(44, 62, 80, 0.28);
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    border-radius: var(--radius-lg);
    margin-bottom: 0;
    position: relative;
    overflow: hidden;
    min-height: 780px;
}

.card-inside {
    z-index: 1;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    animation: heroGlow 4s ease-in-out infinite;
}

@keyframes heroGlow {
    0%, 100% {
        transform: translate(0, 0);
        opacity: 0.3;
    }
    50% {
        transform: translate(10%, 10%);
        opacity: 0.5;
    }
}

/* ============================================
   TYPOGRAPHY
   ============================================ */

.norwegian-greeting {
    display: none;
    font-family: var(--font-heading);
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    color: var(--color-background);
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
    margin-bottom: var(--spacing-sm);
    position: relative;
    z-index: 1;
}

.norwegian-greeting.show {
    display: block;
}

.norwegian-greeting.show::before {
    content: '🇳🇴';
    margin-right: var(--spacing-xs);
    font-size: 1.2em;
}

.name {
    font-family: var(--font-heading);
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 600;
    color: var(--color-background);
    margin-bottom: var(--spacing-md);
    position: relative;
    z-index: 1;
}

.age-container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    position: relative;
    z-index: 1;
}

.age {
    font-family: var(--font-heading);
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 700;
    color: var(--color-background);
    text-shadow: 3px 3px 6px rgba(0, 0, 0, 0.3);
    line-height: 1;
}

.milestone-badge {
    display: none;
    background: var(--color-background);
    color: var(--color-primary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: clamp(0.875rem, 2vw, 1rem);
    font-weight: 600;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.milestone-badge.show {
    display: inline-block;
    animation: shimmer 3s ease-in-out infinite;
}

@keyframes shimmer {
    0%, 100% {
        box-shadow: 0 0 8px rgba(212, 175, 55, 0.35);
    }
    50% {
        box-shadow: 0 0 16px rgba(212, 175, 55, 0.7);
    }
}

.message {
    font-family: var(--font-body);
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.95);
    margin-bottom: var(--spacing-md);
    padding: 0 var(--spacing-sm);
    white-space: pre-line;
    transition: text-shadow var(--duration-normal) ease;
    position: relative;
    z-index: 1;
}

.message:hover {
    text-shadow: 0 0 22px rgba(255, 255, 255, 0.35);
}

.inside-note {
    margin: 0 auto var(--spacing-lg);
    width: min(92%, 520px);
    text-align: left;
    background: rgba(255, 255, 255, 0.92);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid rgba(44, 62, 80, 0.14);
    box-shadow: 0 8px 20px rgba(31, 41, 55, 0.12);
    position: relative;
    z-index: 1;
}

.inside-note-label {
    display: block;
    color: var(--color-secondary);
    font-weight: 600;
    font-size: 0.9rem;
}

.inside-note-text {
    margin-top: 0.45rem;
    min-height: 2.25rem;
    color: var(--color-text);
    font-family: var(--font-heading);
    font-size: 1rem;
    line-height: 1.7;
    font-style: italic;
    white-space: pre-line;
}

/* ============================================
   PHOTO SECTION
   ============================================ */

.photo-container {
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.photo-frame {
    position: relative;
    display: inline-block;
    max-width: 100%;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    transition: transform var(--duration-normal) ease;
}

.photo-frame:hover {
    transform: scale(1.02);
}

.photo {
    display: block;
    width: 100%;
    height: auto;
    max-height: 500px;
    object-fit: cover;
    border-radius: var(--radius-md);
    opacity: 0;
    transition: opacity var(--duration-normal) ease;
}

.photo.loaded {
    opacity: 1;
}

.photo.hidden {
    display: none;
}

.photo-skeleton {
    display: none;
    width: 100%;
    height: 400px;
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s ease-in-out infinite;
    border-radius: var(--radius-md);
}

.photo-skeleton.show {
    display: block;
}

@keyframes skeleton-loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

.photo-error {
    display: none;
    width: 220px;
    height: 220px;
    margin: 0 auto;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    background: rgba(255, 255, 255, 0.92);
    color: var(--color-secondary);
    border: 2px dashed rgba(44, 62, 80, 0.3);
    border-radius: var(--radius-sm);
    text-align: center;
    font-family: var(--font-heading);
    font-size: clamp(2rem, 8vw, 3rem);
    font-weight: 700;
}

.photo-error.show {
    display: flex;
}

/* ============================================
   AUDIO PLAYER
   ============================================ */

.audio-player {
    display: none;
    text-align: center;
    margin-bottom: 0;
    position: relative;
    z-index: 1;
}

.audio-player.show {
    display: block;
}

.audio-button {
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    color: var(--color-background);
    border: none;
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: all var(--duration-normal) ease;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    min-width: 120px;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
}

.audio-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.15);
}

.audio-button:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.audio-button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.audio-button.playing {
    animation: audioPlaying 1s ease-in-out infinite;
}

.audio-button.playing .audio-icon {
    animation: iconPulse 1s ease-in-out infinite;
}

@keyframes audioPlaying {
    0%, 100% {
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    }
    50% {
        box-shadow: 0 6px 12px var(--color-primary);
    }
}

@keyframes iconPulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.2);
    }
}

/* ============================================
   CONFETTI CANVAS
   ============================================ */

.confetti-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 5;
}

/* ============================================
   ERROR DISPLAY
   ============================================ */

.error-display {
    display: none;
    position: fixed;
    top: var(--spacing-md);
    left: 50%;
    transform: translateX(-50%);
    width: min(92%, 560px);
    z-index: 1000;
    background: #fee;
    border: 1px solid var(--color-error);
    border-radius: var(--radius-sm);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    color: var(--color-error);
    font-weight: 600;
    text-align: left;
}

.error-display.show {
    display: block;
}

.error-display h3 {
    margin-bottom: var(--spacing-xs);
}

.error-display p {
    margin-bottom: var(--spacing-xs);
}

/* ============================================
   SCROLL ANIMATIONS
   ============================================ */

.scroll-reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity var(--duration-slow) ease, transform var(--duration-slow) ease;
}

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

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

/* Mobile: keep closed cover on one screen */
@media (max-width: 767px) {
    html,
    body {
        height: 100dvh;
    }

    body {
        overflow: hidden;
    }

    .birthday-card {
        width: 100%;
        max-width: none;
        min-height: 100dvh;
        margin: 0;
        padding: 0;
    }

    .card-stage {
        margin-bottom: 0;
        min-height: 100dvh;
    }

    .card-book {
        height: 100dvh;
        min-height: 100dvh;
        overflow: hidden;
        border-radius: 0;
        box-shadow: none;
    }

    .hero {
        min-height: 100%;
        padding: var(--spacing-lg) var(--spacing-sm);
        border-radius: 0;
    }

    .card-actions {
        display: none;
    }

    .card-cover {
        border-radius: 0;
    }

    body.card-open-mobile {
        overflow-x: hidden;
        overflow-y: auto;
    }

    body.card-open-mobile .birthday-card {
        min-height: auto;
        padding: 0.5rem;
    }

    body.card-open-mobile .card-book {
        height: auto;
        min-height: 0;
        overflow: visible;
        border-radius: var(--radius-lg);
        box-shadow:
            0 24px 40px rgba(44, 62, 80, 0.18),
            0 0 0 1px rgba(255, 255, 255, 0.65) inset;
    }

    body.card-open-mobile .hero,
    body.card-open-mobile .card-cover {
        border-radius: var(--radius-lg);
    }

    body.card-open-mobile .card-actions {
        display: block;
        margin-top: var(--spacing-sm);
    }
}

/* Tablet and larger */
@media (min-width: 768px) {
    .birthday-card {
        margin: var(--spacing-xl) auto;
        padding: 0;
    }

    .card-book {
        min-height: 820px;
    }

    .hero {
        padding: var(--spacing-xl) var(--spacing-lg);
    }

    .message {
        padding: 0 var(--spacing-lg);
    }
}

/* Desktop and larger */
@media (min-width: 1024px) {
    .photo {
        max-height: 600px;
    }
}

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

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

/* Focus styles for keyboard navigation */
.audio-button:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 2px;
}

.card-cover:focus-visible,
.card-toggle-button:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 3px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .birthday-card {
        border: 2px solid var(--color-text);
    }

    .audio-button {
        border: 2px solid var(--color-background);
    }
}