/* ==========================================================================
   Design System & Theme Tokens
   ========================================================================== */
:root {
    --bg-main: #0B0F19;
    --bg-card: rgba(22, 29, 45, 0.75);
    --bg-card-hover: rgba(30, 41, 64, 0.88);
    --border-glass: rgba(255, 255, 255, 0.12);
    --border-glow: rgba(255, 182, 193, 0.35);
    
    --accent-gold: #F5D061;
    --accent-rose: #FF7597;
    --accent-purple: #9D4EDD;
    --accent-cyan: #4CC9F0;
    
    --text-main: #F8FAFC;
    --text-muted: #94A3B8;
    --text-gold: #FDE047;
    
    --font-heading: 'Playfair Display', Georgia, serif;
    --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    
    --shadow-glow: 0 10px 40px -10px rgba(255, 117, 151, 0.25);
    --shadow-card: 0 20px 40px rgba(0, 0, 0, 0.4);
    
    --radius-lg: 24px;
    --radius-md: 16px;
    --radius-sm: 12px;
    
    --transition-smooth: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
    --transition-flip: transform 0.8s cubic-bezier(0.34, 1.56, 0.64, 1);
}

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
}

html {
    height: -webkit-fill-available;
}

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    font-family: var(--font-body);
    min-height: 100vh;
    min-height: -webkit-fill-available;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    overflow-x: hidden;
    position: relative;
    padding: max(20px, env(safe-area-inset-top)) max(16px, env(safe-area-inset-right)) max(20px, env(safe-area-inset-bottom)) max(16px, env(safe-area-inset-left));
}

/* Ambient Background Glow Effects */
.background-glow {
    position: fixed;
    border-radius: 50%;
    filter: blur(120px);
    z-index: 0;
    pointer-events: none;
    opacity: 0.4;
    animation: floatGlow 14s infinite alternate ease-in-out;
}

.glow-1 {
    width: 450px;
    height: 450px;
    background: radial-gradient(circle, var(--accent-rose), transparent 70%);
    top: -100px;
    left: -100px;
}

.glow-2 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--accent-purple), transparent 70%);
    bottom: -150px;
    right: -100px;
    animation-delay: -5s;
}

.glow-3 {
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, var(--accent-gold), transparent 70%);
    top: 40%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-delay: -9s;
}

@keyframes floatGlow {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(40px, 30px) scale(1.15); }
}

/* Canvas Confetti */
#confetti-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: 9999;
}

/* Common Utility Classes */
.hidden {
    display: none !important;
}

.glass-card {
    background: var(--bg-card);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    position: relative;
    z-index: 1;
}

/* ==========================================================================
   Passcode Screen Modal
   ========================================================================== */
.screen-overlay {
    position: fixed;
    inset: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: max(16px, env(safe-area-inset-top)) 16px max(16px, env(safe-area-inset-bottom)) 16px;
    background: rgba(11, 15, 25, 0.88);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    transition: opacity 0.4s ease, visibility 0.4s ease;
}

.passcode-card {
    width: 100%;
    max-width: 400px;
    padding: 32px 24px;
    text-align: center;
    border: 1px solid var(--border-glow);
    animation: scaleIn 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.92) translateY(15px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}

.lock-icon-wrapper {
    width: 64px;
    height: 64px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, rgba(255, 117, 151, 0.2), rgba(157, 78, 221, 0.2));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    border: 1px solid var(--border-glass);
    box-shadow: var(--shadow-glow);
}

.passcode-title {
    font-family: var(--font-heading);
    font-size: 26px;
    margin-bottom: 6px;
    font-weight: 700;
}

.highlight-name {
    background: linear-gradient(135deg, var(--accent-rose), var(--accent-gold));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.passcode-subtitle {
    color: var(--text-muted);
    font-size: 14px;
    margin-bottom: 20px;
    line-height: 1.4;
}

.input-hint {
    font-size: 11px;
    color: rgba(255, 255, 255, 0.4);
    display: block;
    margin-top: 4px;
}

.pin-display-container {
    margin-bottom: 16px;
}

.pin-display-container input {
    width: 100%;
    padding: 14px;
    background: rgba(10, 14, 23, 0.85);
    border: 2px solid var(--border-glass);
    border-radius: var(--radius-sm);
    color: var(--text-gold);
    font-size: 24px;
    letter-spacing: 6px;
    text-align: center;
    outline: none;
    transition: var(--transition-smooth);
    font-family: monospace;
}

.pin-display-container input:focus {
    border-color: var(--accent-rose);
    box-shadow: 0 0 15px rgba(255, 117, 151, 0.3);
}

.error-message {
    color: #FF5252;
    font-size: 13px;
    margin-bottom: 16px;
    animation: shake 0.4s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20%, 60% { transform: translateX(-8px); }
    40%, 80% { transform: translateX(8px); }
}

/* Touch & Mouse Keypad */
.keypad {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-bottom: 20px;
    touch-action: manipulation;
}

.key-btn {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-sm);
    color: var(--text-main);
    font-size: 22px;
    font-weight: 600;
    padding: 14px 0;
    min-height: 52px;
    cursor: pointer;
    transition: var(--transition-smooth);
    user-select: none;
    -webkit-user-select: none;
}

.key-btn:hover {
    background: rgba(255, 255, 255, 0.14);
    transform: translateY(-2px);
}

.key-btn:active, .key-btn.active-key {
    background: rgba(255, 117, 151, 0.3) !important;
    border-color: var(--accent-rose);
    transform: scale(0.94);
}

.action-key {
    color: var(--text-muted);
    font-size: 16px;
}

.primary-btn {
    width: 100%;
    padding: 16px;
    min-height: 52px;
    border: none;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--accent-rose), var(--accent-purple));
    color: #FFF;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    box-shadow: 0 8px 25px rgba(255, 117, 151, 0.4);
    transition: var(--transition-smooth);
    touch-action: manipulation;
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 30px rgba(255, 117, 151, 0.6);
}

.secondary-btn {
    width: 100%;
    padding: 14px;
    min-height: 48px;
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-muted);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-smooth);
    margin-top: 10px;
}

.secondary-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    color: #FFF;
}

/* ==========================================================================
   Main Application Workspace
   ========================================================================== */
.main-container {
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
    z-index: 10;
    position: relative;
    padding: 10px 0;
}

.app-header {
    text-align: center;
    margin-bottom: 30px;
}

.badge {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid var(--border-glass);
    border-radius: 30px;
    font-size: 13px;
    font-weight: 600;
    color: var(--accent-gold);
    margin-bottom: 12px;
    letter-spacing: 0.5px;
}

.main-title {
    font-family: var(--font-heading);
    font-size: 36px;
    margin-bottom: 10px;
    line-height: 1.25;
    background: linear-gradient(135deg, #FFFFFF 30%, var(--text-muted) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.emoji-icon {
    display: inline-block;
    background: none;
    -webkit-background-clip: initial;
    background-clip: initial;
    -webkit-text-fill-color: initial;
    color: initial;
}

.main-description {
    color: var(--text-muted);
    font-size: 15px;
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

.sync-banner {
    background: rgba(76, 201, 240, 0.15);
    border: 1px solid rgba(76, 201, 240, 0.3);
    color: var(--accent-cyan);
    padding: 12px 20px;
    border-radius: var(--radius-sm);
    text-align: center;
    font-size: 13px;
    margin-bottom: 20px;
}

.spinner {
    display: inline-block;
    animation: spin 1.5s infinite linear;
}

@keyframes spin {
    100% { transform: rotate(360deg); }
}

.status-banner {
    background: linear-gradient(135deg, rgba(245, 208, 97, 0.15), rgba(157, 78, 221, 0.15));
    border: 1px solid var(--border-glow);
    border-radius: var(--radius-md);
    padding: 16px 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    max-width: 600px;
    margin: 0 auto 30px auto;
    animation: fadeIn 0.5s ease;
}

.status-icon {
    font-size: 32px;
}

.status-text h3 {
    font-size: 16px;
    color: var(--accent-gold);
    margin-bottom: 2px;
}

.status-text p {
    font-size: 13px;
    color: var(--text-muted);
}

/* ==========================================================================
   3D Card Selection Grid
   ========================================================================== */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-bottom: 30px;
    perspective: 1200px; /* Essential for 3D card flip */
    -webkit-perspective: 1200px;
}

.card-item {
    height: 380px;
    position: relative;
    cursor: pointer;
    touch-action: manipulation;
}

.card-inner {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    -webkit-transform-style: preserve-3d;
    transition: var(--transition-flip);
    border-radius: var(--radius-lg);
}

.card-item:hover:not(.flipped):not(.disabled) .card-inner {
    transform: translateY(-8px) rotateY(10deg);
}

.card-item.flipped .card-inner {
    transform: rotateY(180deg);
    -webkit-transform: rotateY(180deg);
}

/* Card Front & Back Face */
.card-face {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 24px 16px;
    text-align: center;
    border: 1px solid var(--border-glass);
    box-shadow: var(--shadow-card);
    background: var(--bg-card);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
}

/* Front Face Styling */
.card-face-front {
    background: linear-gradient(165deg, rgba(30, 41, 64, 0.75), rgba(15, 23, 42, 0.92));
    transition: border-color 0.3s ease;
}

.card-item:hover:not(.disabled) .card-face-front {
    border-color: var(--border-glow);
}

.card-icon-container {
    width: 84px;
    height: 84px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.12), transparent 70%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 44px;
    margin-bottom: 18px;
    border: 1px solid var(--border-glass);
    box-shadow: 0 0 25px rgba(255, 255, 255, 0.05);
    transition: transform 0.3s ease;
}

.card-item:hover:not(.disabled) .card-icon-container {
    transform: scale(1.1);
}

.card-front-title {
    font-family: var(--font-heading);
    font-size: 22px;
    margin-bottom: 6px;
    color: var(--text-main);
}

.card-front-subtitle {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 20px;
    line-height: 1.4;
}

.tap-to-open-badge {
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.8px;
    text-transform: uppercase;
    color: var(--accent-rose);
    padding: 8px 16px;
    border-radius: 20px;
    background: rgba(255, 117, 151, 0.12);
    border: 1px solid rgba(255, 117, 151, 0.25);
}

/* Back Face Styling (Revealed Gift) */
.card-face-back {
    background: linear-gradient(145deg, rgba(26, 32, 53, 0.96), rgba(13, 17, 28, 0.98));
    transform: rotateY(180deg);
    -webkit-transform: rotateY(180deg);
    border: 2px solid var(--accent-gold);
    box-shadow: 0 0 35px rgba(245, 208, 97, 0.25);
    justify-content: space-between;
}

.claimed-ribbon {
    position: absolute;
    top: 14px;
    right: 14px;
    background: var(--accent-gold);
    color: #000;
    font-size: 10px;
    font-weight: 800;
    padding: 4px 10px;
    border-radius: 12px;
    text-transform: uppercase;
}

.back-icon {
    font-size: 38px;
    margin-top: 10px;
}

.back-title {
    font-family: var(--font-heading);
    font-size: 18px;
    color: var(--accent-gold);
    margin-bottom: 6px;
}

.back-desc {
    font-size: 13px;
    color: var(--text-main);
    line-height: 1.4;
    margin-bottom: 10px;
}

.back-details {
    font-size: 11px;
    color: var(--text-muted);
    background: rgba(0, 0, 0, 0.35);
    padding: 10px;
    border-radius: var(--radius-sm);
    width: 100%;
}

/* Disabled State for Unselected Cards */
.card-item.disabled {
    cursor: not-allowed;
    opacity: 0.35;
    filter: grayscale(0.85);
    -webkit-filter: grayscale(0.85);
    pointer-events: none;
    transform: scale(0.96);
}

.disabled-lock-overlay {
    position: absolute;
    inset: 0;
    z-index: 5;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(11, 15, 25, 0.75);
    border-radius: var(--radius-lg);
}

.disabled-lock-overlay span {
    font-size: 28px;
    margin-bottom: 6px;
}

.disabled-lock-overlay p {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-muted);
}

/* ==========================================================================
   Revealed Details Section
   ========================================================================== */
.revealed-section {
    margin-top: 20px;
    animation: slideUp 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.revelation-card {
    padding: 32px 24px;
    border: 2px solid var(--accent-gold);
    background: linear-gradient(135deg, rgba(22, 29, 45, 0.92), rgba(15, 23, 42, 0.97));
    text-align: center;
}

.revelation-tag {
    display: inline-block;
    color: var(--accent-gold);
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
}

.revealed-title {
    font-family: var(--font-heading);
    font-size: 28px;
    color: #FFF;
    margin-bottom: 12px;
}

.revealed-desc {
    font-size: 15px;
    color: var(--text-main);
    max-width: 650px;
    margin: 0 auto 18px auto;
    line-height: 1.6;
}

.revealed-details-box {
    background: rgba(0, 0, 0, 0.45);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    padding: 16px 20px;
    display: inline-block;
    color: var(--accent-cyan);
    font-weight: 600;
    font-size: 14px;
    margin-bottom: 16px;
}

.revelation-footer {
    border-top: 1px solid var(--border-glass);
    padding-top: 14px;
    color: var(--text-muted);
    font-size: 13px;
}

/* Admin Reset Modal */
.reset-card {
    width: 100%;
    max-width: 380px;
    padding: 30px 24px;
    text-align: center;
}

.reset-card h2 {
    font-size: 20px;
    margin-bottom: 8px;
}

.reset-card p {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 18px;
}

.reset-card input {
    width: 100%;
    padding: 14px;
    background: rgba(10, 14, 23, 0.85);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-sm);
    color: var(--text-main);
    font-size: 16px;
    text-align: center;
    margin-bottom: 16px;
    outline: none;
}

.reset-card input:focus {
    border-color: var(--accent-rose);
}

.modal-buttons {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* ==========================================================================
   Footer & Admin
   ========================================================================== */
.app-footer {
    text-align: center;
    padding: 24px 0 10px 0;
    color: var(--text-muted);
    font-size: 13px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.reset-link {
    background: none;
    border: none;
    color: rgba(255, 255, 255, 0.35);
    font-size: 12px;
    cursor: pointer;
    transition: var(--transition-smooth);
    padding: 6px 12px;
    border-radius: 6px;
    touch-action: manipulation;
}

.reset-link:hover {
    color: var(--accent-rose);
    background: rgba(255, 255, 255, 0.08);
}

/* ==========================================================================
   Mobile Optimization (e.g. iPhone 17, iPhone Pro, Smartphones)
   ========================================================================== */
@media (max-width: 900px) {
    .main-title {
        font-size: 28px;
    }
    
    .cards-grid {
        grid-template-columns: 1fr;
        max-width: 360px;
        margin-left: auto;
        margin-right: auto;
        gap: 24px;
    }
    
    .card-item {
        height: 330px;
    }
    
    .card-icon-container {
        width: 76px;
        height: 76px;
        font-size: 40px;
        margin-bottom: 14px;
    }

    .revelation-card {
        padding: 24px 16px;
    }
    
    .revealed-title {
        font-size: 22px;
    }
    
    .key-btn {
        min-height: 56px; /* Optimized touch target for modern mobile screens */
        font-size: 24px;
    }
}