:root {
    --primary: #006b7d;
    --secondary: #00a3ad;
    --accent: #7fd1d9;
    --light: #c1e6eb;
    --white: #f5fbfc;
    --bg: #eaf6f8;
    --success: #4caf50;
    --error: #f44336;
    --shadow-light: rgba(0, 107, 125, 0.1);
    --shadow-medium: rgba(0, 107, 125, 0.15);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--primary);
    background: linear-gradient(135deg, var(--bg) 0%, var(--white) 100%);
    margin: 0;
    padding: 0;
    min-height: 100vh;
    scroll-behavior: smooth;
}

/* Navigation */
.nav {
    background: rgba(245, 251, 252, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--light);
    transition: var(--transition);
}

.nav.scrolled {
    box-shadow: 0 2px 20px var(--shadow-light);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}

.nav-logo:hover {
    color: var(--secondary);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-links a:hover {
    color: var(--secondary);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--secondary);
    transition: var(--transition);
}

.nav-links a:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 3px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--primary);
    transition: var(--transition);
}

/* Main Content */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    margin-top: 80px; /* Account for fixed nav */
}

/* Hero Section */
.hero {
    text-align: center;
    margin-bottom: 4rem;
    padding: 3rem 0;
    background: linear-gradient(135deg, var(--white) 0%, var(--light) 100%);
    border-radius: 20px;
    box-shadow: 0 10px 40px var(--shadow-light);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, var(--accent) 0%, transparent 70%);
    opacity: 0.1;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

.hero h1 {
    /* 調整：字體縮小為原來最大 4rem 的 50% 以下，改為最大 2rem；最小值由 2.5rem -> 1.2rem 以在小螢幕保留層級但不佔空間 */
    font-size: clamp(1.2rem, 3vw, 2rem);
    font-weight: 600; /* 略降粗度，避免在縮小後過於厚重 */
    margin-bottom: 0.75rem;
    color: var(--primary);
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.25; /* 縮小後調整行高提升可讀性 */
}

.subtitle {
    /* 調整：副標字體也同步縮減，維持層級差異比 h1 小約 30% */
    font-size: clamp(0.85rem, 2vw, 1.1rem);
    color: var(--secondary);
    font-weight: 400;
    margin-bottom: 1.5rem;
    line-height: 1.4;
}

.hero-features {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.hero-feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary);
    font-weight: 500;
}

.hero-feature i {
        color: var(--secondary);
        font-size: 1rem; /* 由 1.2rem 略降，配合整體縮小 */
}

/* 更小視窗下再次微調（避免 clamp 中 vw 導致過大） */
@media (max-width: 480px) {
    .hero h1 { font-size: 1.35rem; }
    .subtitle { font-size: 0.9rem; }
}

/* App Grid */
.apps-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.app-card {
    background: var(--white);
    border-radius: 20px;
    box-shadow: 0 5px 25px var(--shadow-light);
    padding: 2rem;
    transition: var(--transition);
    border: 1px solid var(--light);
    position: relative;
    overflow: hidden;
}

.app-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--secondary) 0%, var(--accent) 100%);
    transform: scaleX(0);
    transition: var(--transition);
}

.app-card:hover::before {
    transform: scaleX(1);
}

.app-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 50px var(--shadow-medium);
}

.app-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.app-icon {
    width: 80px;
    height: 80px;
    border-radius: 20px;
    object-fit: cover;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
    transition: var(--transition);
}

.app-card:hover .app-icon {
    transform: scale(1.05);
}

.app-info h2 {
    font-size: 1.5rem;
    margin: 0 0 0.5rem 0;
    color: var(--primary);
    font-weight: 600;
}

.app-badge {
    display: inline-block;
    background: var(--accent);
    color: var(--primary);
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 500;
}

.app-description {
    color: var(--secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.app-features {
    margin-bottom: 2rem;
}

.app-features h4 {
    color: var(--primary);
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.app-features ul {
    list-style: none;
    padding: 0;
}

.app-features li {
    padding: 0.5rem 0;
    color: var(--secondary);
    position: relative;
    padding-left: 1.5rem;
}

.app-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--secondary);
    font-weight: bold;
}

.app-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.app-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--secondary);
    color: var(--white);
    text-decoration: none;
    border-radius: 12px;
    font-weight: 600;
    transition: var(--transition);
    flex-grow: 1;
    justify-content: center;
    min-width: 140px;
    box-shadow: 0 4px 15px rgba(0, 163, 173, 0.3);
}

.app-link.ios {
    background: linear-gradient(135deg, #007aff 0%, #0056cc 100%);
}

.app-link.android {
    background: linear-gradient(135deg, #3ddc84 0%, #2bbd6e 100%);
}

.app-link:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 163, 173, 0.4);
}

.app-link.ios:hover {
    box-shadow: 0 8px 25px rgba(0, 122, 255, 0.4);
}

.app-link.android:hover {
    box-shadow: 0 8px 25px rgba(61, 220, 132, 0.4);
}

/* Coming Soon Cards */
.coming-soon {
    opacity: 0.8;
    position: relative;
}

.coming-soon::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, transparent 0%, rgba(199, 230, 235, 0.3) 100%);
    border-radius: 20px;
    pointer-events: none;
}

/* Footer */
footer {
    text-align: center;
    margin-top: 4rem;
    padding: 2rem 0;
    border-top: 2px solid var(--light);
    color: var(--secondary);
    font-size: 0.9rem;
    background: linear-gradient(135deg, var(--white) 0%, var(--light) 100%);
    border-radius: 20px 20px 0 0;
}

/* Simplified app grid for homepage */
.simple-grid {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

/* Home entry vertical list */
.home-entry-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    margin-bottom: 3rem;
}

.home-entry-list .app-mini-card {
    flex-direction: row;
    align-items: center;
    justify-content: flex-start;
    padding: 1.25rem 1.5rem;
    border-radius: 18px;
}

.home-entry-list .app-mini-card .mini-link {
    flex-direction: row;
    align-items: center;
    gap: 1rem;
}

/* Homepage entry icon colors */
.home-entry-icon { font-size: 48px; }
.icon-apps { color: #00a3ad; }
.icon-games { color: #ff8f00; }
.icon-contact { color: #0077cc; }
.icon-privacy { color: #2e7d32; }
.icon-terms { color: #c2185b; }

/* Mini game icons (games page) */
.mini-icon { font-size: 64px; }
.icon-lightning { color: #ff8f00; } /* 反應速度：琥珀橙 */
.icon-puzzle { color: #0077cc; }    /* 益智拼圖：藍色 */
.icon-brain { color: #7b1fa2; }     /* 記憶翻牌：紫色 */
.icon-hammer { color: #43a047; }    /* 打地鼠：綠色 */
.icon-2048 { color: #d81b60; }      /* 2048：洋紅 */
/* 新增：四個新遊戲 icon 顏色區分 */
.icon-snake { color: #00897b; }      /* 貪食蛇：藍綠色 */
.icon-tetris { color: #3949ab; }     /* 俄羅斯方塊：靛藍 */
.icon-sudoku { color: #6d4c41; }     /* 數獨：棕色 */
.icon-ttt { color: #c2185b; }        /* 井字遊戲 AI：洋紅深色 */

.home-entry-list .app-mini-card i {
    width: 64px;
    height: 64px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.home-entry-list .mini-name {
    font-size: 1.1rem;
    text-align: left;
    margin: 0;
}

.home-entry-list .app-mini-card p {
    margin: 0 0 0 auto;
    font-size: 0.85rem;
    max-width: 340px;
    text-align: right;
    color: var(--secondary);
}

@media (max-width: 760px) {
    .home-entry-list .app-mini-card {
        flex-direction: column;
        align-items: flex-start;
    /* Snake 手機正方形與防裁切 */
    #snake-canvas { width: 100% !important; max-width: 100%; height: auto; aspect-ratio: 1 / 1; }
        gap: 0.5rem;
    }
    .home-entry-list .app-mini-card p {
        text-align: left;
        margin: 0;
        max-width: 100%;
    }
    .home-entry-list .app-mini-card .mini-link {
        flex-direction: row;
    }
}

.app-mini-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    background: var(--white);
    border: 1px solid var(--light);
    border-radius: 20px;
    padding: 1.25rem;
    box-shadow: 0 5px 25px var(--shadow-light);
    text-decoration: none;
    color: var(--primary);
    transition: var(--transition);
}

.app-mini-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 50px var(--shadow-medium);
}

.app-mini-card img {
    width: 96px;
    height: 96px;
    border-radius: 20px;
    object-fit: cover;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.mini-name {
    font-size: 1rem;
    text-align: center;
    margin: 0.25rem 0 0.5rem 0;
}

.mini-buttons {
    display: flex;
    gap: 0.5rem;
}

.store-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 36px;
    border-radius: 10px;
    color: #fff;
    text-decoration: none;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
}

.store-btn.ios { background: linear-gradient(135deg, #007aff 0%, #0056cc 100%); }
.store-btn.android { background: linear-gradient(135deg, #3ddc84 0%, #2bbd6e 100%); }

.store-btn:hover { transform: translateY(-2px); }

/* Mini card inner link (image + name) */
.app-mini-card .mini-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: inherit;
}

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

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

/* Loading Animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s ease-in-out infinite;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(245, 251, 252, 0.98);
        backdrop-filter: blur(10px);
        flex-direction: column;
        padding: 1rem;
        box-shadow: 0 10px 30px var(--shadow-light);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-toggle {
        display: flex;
    }

    .container {
        padding: 1rem;
        margin-top: 70px;
    }

    .hero {
        padding: 2rem 1rem;
        margin-bottom: 2rem;
    }

    .hero-features {
        /* 手機保持水平佈局，置中；若超出寬度，可橫向捲動但不換行 */
        flex-direction: row;
        flex-wrap: nowrap;
        justify-content: center; /* 置中顯示 */
        gap: 1rem;
        overflow-x: auto;
        padding: .25rem 0;
        -webkit-overflow-scrolling: touch;
    }
    .hero-features::-webkit-scrollbar { height: 6px; }
    .hero-features::-webkit-scrollbar-track { background: transparent; }
    .hero-features::-webkit-scrollbar-thumb { background: var(--light); border-radius: 3px; }
    .hero-feature { flex: 0 0 auto; display: inline-flex; white-space: nowrap; }
    .hero-feature i { font-size: 1rem; }
    .hero-feature span { font-size: .95rem; }

    .apps-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .app-card {
        padding: 1.5rem;
    }

    .app-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .app-links {
        flex-direction: column;
    }

    .app-link {
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .app-icon {
        width: 60px;
        height: 60px;
    }

    .app-features li {
        font-size: 0.9rem;
    }
}

/* App Store Icon Loading Styles */
.icon-loading {
    animation: iconSpin 1s linear infinite;
}

@keyframes iconSpin {
    from { transform: translate(-50%, -50%) rotate(0deg); }
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

.app-icon {
    transition: opacity 0.3s ease, filter 0.3s ease;
}

.app-icon.loading {
    opacity: 0.6;
    filter: blur(1px);
}

/* Development Tools Panel */
#dev-panel {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
}

#dev-panel button:hover {
    opacity: 0.8;
    transform: translateY(-1px);
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *, ::before, ::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .icon-loading {
        animation: none;
    }
}

/* Mobile game boards fit: prevent right-side clipping inside padded cards */
@media (max-width: 768px) {
    /* 2048 board: use container width instead of viewport width */
    #g-grid { width: min(100%, 360px) !important; height: auto !important; aspect-ratio: 1 / 1 !important; }
    /* Sudoku board: always fit card content width */
    #sudoku-board { width: 100% !important; max-width: 450px !important; }
}

/* High contrast mode */
@media (prefers-contrast: high) {
    :root {
        --primary: #003d47;
        --secondary: #006b7d;
        --light: #9ab8bf;
    }
}

/* Dark mode support (future enhancement) */
@media (prefers-color-scheme: dark) {
    /* Dark mode styles can be added here */
}

/* Print styles */
@media print {
    .nav, footer {
        display: none;
    }
    
    .container {
        margin-top: 0;
        max-width: none;
    }
    
    .app-card {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ccc;
    }
}

/* Screen-reader only utility */
.sr-only {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

/* AdSense skeleton & container (pending approval) */
.ads-section { margin: 2rem 0 3rem; }
.ad-container {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 140px;
    background: #f7f9fa;
    border: 1px dashed #b7cdd2;
    border-radius: 16px;
    box-shadow: 0 4px 18px var(--shadow-light);
    overflow: hidden;
    transition: var(--transition);
}
.ad-container.pending-approval:hover {
    background: #eef5f7;
}
.ad-skeleton {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: .5rem;
    font-size: .9rem;
    color: #5e7d84;
    animation: pulse 1.6s ease-in-out infinite;
    padding: .75rem 1.25rem;
    border-radius: 12px;
    background: linear-gradient(135deg,#e3eff2 0%,#f5fbfc 100%);
    box-shadow: inset 0 0 0 1px #d4e6ea;
}
@keyframes pulse {
    0%,100% { opacity: 0.65; }
    50% { opacity: 1; }
}
.ad-container.approved { border: none; background: transparent; box-shadow: none; }
.ad-container.approved .ad-skeleton { display: none; }
@media (prefers-reduced-motion: reduce) {
    .ad-skeleton { animation: none; }
}