/* Modern CSS Reset & Design System */
:root {
    /* Fonts */
    --font-heading: 'Outfit', 'Space Grotesk', -apple-system, sans-serif;
    --font-body: 'Plus Jakarta Sans', -apple-system, sans-serif;
    --font-mono: 'Space Grotesk', monospace;

    /* Theme Tokens - Default Cyber Neon */
    --bg-base: #0a0b10;
    --bg-card: rgba(18, 20, 32, 0.7);
    --bg-card-border: rgba(255, 255, 255, 0.12);
    --text-main: #f1f5f9;
    --text-sub: #94a3b8;
    
    --primary-glow: #8b5cf6;
    --secondary-glow: #06b6d4;
    --accent-gradient: linear-gradient(135deg, #a855f7 0%, #06b6d4 50%, #3b82f6 100%);
    --button-primary-bg: linear-gradient(135deg, #7c3aed 0%, #2563eb 100%);
    --button-primary-hover: linear-gradient(135deg, #8b5cf6 0%, #3b82f6 100%);
    
    --particle-color: 139, 92, 246; /* RGB for JS canvas */

    /* Glass Effect */
    --glass-backdrop: blur(16px) saturate(180%);
    --glass-shadow: 0 20px 50px rgba(0, 0, 0, 0.5), inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

/* Color Theme Overrides */
[data-theme="aurora"] {
    --bg-base: #06130d;
    --bg-card: rgba(10, 31, 22, 0.75);
    --bg-card-border: rgba(16, 185, 129, 0.2);
    --primary-glow: #10b981;
    --secondary-glow: #06b6d4;
    --accent-gradient: linear-gradient(135deg, #34d399 0%, #06b6d4 50%, #10b981 100%);
    --button-primary-bg: linear-gradient(135deg, #059669 0%, #0d9488 100%);
    --particle-color: 16, 185, 129;
}

[data-theme="sunset"] {
    --bg-base: #140b10;
    --bg-card: rgba(33, 16, 25, 0.75);
    --bg-card-border: rgba(244, 63, 94, 0.2);
    --primary-glow: #f43f5e;
    --secondary-glow: #fb923c;
    --accent-gradient: linear-gradient(135deg, #fb7185 0%, #fb923c 50%, #f43f5e 100%);
    --button-primary-bg: linear-gradient(135deg, #e11d48 0%, #ea580c 100%);
    --particle-color: 244, 63, 94;
}

[data-theme="solar"] {
    --bg-base: #121008;
    --bg-card: rgba(31, 26, 12, 0.75);
    --bg-card-border: rgba(245, 158, 11, 0.2);
    --primary-glow: #f59e0b;
    --secondary-glow: #eab308;
    --accent-gradient: linear-gradient(135deg, #fbbf24 0%, #f59e0b 50%, #d97706 100%);
    --button-primary-bg: linear-gradient(135deg, #d97706 0%, #b45309 100%);
    --particle-color: 245, 158, 11;
}

[data-theme="cosmic"] {
    --bg-base: #0a0a18;
    --bg-card: rgba(18, 18, 42, 0.75);
    --bg-card-border: rgba(99, 102, 241, 0.25);
    --primary-glow: #6366f1;
    --secondary-glow: #ec4899;
    --accent-gradient: linear-gradient(135deg, #818cf8 0%, #ec4899 50%, #6366f1 100%);
    --button-primary-bg: linear-gradient(135deg, #4f46e5 0%, #db2777 100%);
    --particle-color: 99, 102, 241;
}

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

body {
    background-color: var(--bg-base);
    color: var(--text-main);
    font-family: var(--font-body);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    position: relative;
    transition: background-color 0.6s ease;
}

/* Interactive Canvas Background */
#particle-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
}

/* App Header */
.app-header {
    position: relative;
    z-index: 10;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 2.5rem;
    backdrop-filter: var(--glass-backdrop);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: -0.02em;
}

.brand-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--primary-glow);
    box-shadow: 0 0 12px var(--primary-glow);
    animation: pulseGlow 2s infinite alternate;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.time-badge {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 0.8rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    font-size: 0.85rem;
    font-family: var(--font-mono);
    color: var(--text-sub);
}

.icon-btn {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-main);
    width: 38px;
    height: 38px;
    border-radius: 10px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    transition: all 0.2s ease;
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-1px);
}

/* Theme Picker */
.theme-picker {
    position: relative;
}

.theme-trigger-btn {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.12);
    padding: 0.45rem 0.9rem;
    border-radius: 10px;
    color: var(--text-main);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.theme-trigger-btn:hover {
    background: rgba(255, 255, 255, 0.12);
}

.theme-swatch {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--primary-glow);
    box-shadow: 0 0 8px var(--primary-glow);
}

.theme-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    width: 170px;
    background: rgba(18, 20, 32, 0.95);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 12px;
    padding: 0.4rem;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
    z-index: 100;
    transition: opacity 0.2s, transform 0.2s;
}

.theme-dropdown[hidden] {
    display: none;
}

.theme-option {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.5rem 0.75rem;
    border: none;
    background: transparent;
    color: var(--text-sub);
    font-size: 0.85rem;
    border-radius: 8px;
    cursor: pointer;
    text-align: left;
    transition: all 0.15s ease;
}

.theme-option:hover, .theme-option.active {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-main);
}

.swatch {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}
.swatch.cyber { background: #8b5cf6; }
.swatch.aurora { background: #10b981; }
.swatch.sunset { background: #f43f5e; }
.swatch.solar { background: #f59e0b; }
.swatch.cosmic { background: #6366f1; }

/* Main Layout */
.main-container {
    position: relative;
    z-index: 5;
    flex: 1;
    max-width: 900px;
    width: 100%;
    margin: 0 auto;
    padding: 3rem 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
    justify-content: center;
}

/* Hero Section Card */
.hero-card {
    position: relative;
    background: var(--bg-card);
    backdrop-filter: var(--glass-backdrop);
    border: 1px solid var(--bg-card-border);
    border-radius: 28px;
    padding: 3.5rem 2.5rem;
    box-shadow: var(--glass-shadow);
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.8rem;
    overflow: hidden;
    transition: border-color 0.4s ease, transform 0.3s ease;
}

.card-glow {
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 50% 30%, rgba(var(--particle-color), 0.15) 0%, transparent 60%);
    pointer-events: none;
    transition: background 0.6s ease;
}

/* Greeting Badge */
.greeting-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 1rem;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-sub);
    letter-spacing: 0.02em;
}

.ping-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--primary-glow);
    box-shadow: 0 0 10px var(--primary-glow);
}

/* Title & Subtitle */
.headline-wrapper {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    max-width: 650px;
}

.main-title {
    font-family: var(--font-heading);
    font-size: clamp(3.5rem, 8vw, 5.5rem);
    font-weight: 900;
    line-height: 1.05;
    letter-spacing: -0.03em;
    user-select: none;
    transition: transform 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.gradient-text {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 4px 20px rgba(var(--particle-color), 0.3));
}

.sub-title {
    font-size: 1.15rem;
    color: var(--text-sub);
    line-height: 1.6;
    font-weight: 400;
}

/* Language Pills */
.lang-pills-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.5rem;
    max-width: 680px;
    margin-top: 0.5rem;
}

.lang-pill {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    color: var(--text-sub);
    padding: 0.45rem 0.9rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    user-select: none;
}

.lang-pill:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-main);
    transform: translateY(-2px);
}

.lang-pill.active {
    background: rgba(255, 255, 255, 0.15);
    border-color: var(--primary-glow);
    color: #fff;
    box-shadow: 0 0 15px rgba(var(--particle-color), 0.4);
}

/* Action Bar */
.action-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-top: 0.5rem;
}

.primary-btn, .secondary-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.85rem 1.6rem;
    border-radius: 14px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s cubic-bezier(0.165, 0.84, 0.44, 1);
    border: none;
}

.primary-btn {
    background: var(--button-primary-bg);
    color: #fff;
    box-shadow: 0 8px 25px rgba(var(--particle-color), 0.35);
}

.primary-btn:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 12px 30px rgba(var(--particle-color), 0.5);
}

.secondary-btn {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-main);
}

.secondary-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    transform: translateY(-3px);
    border-color: rgba(255, 255, 255, 0.25);
}

.glow-btn:hover {
    border-color: var(--primary-glow);
    box-shadow: 0 0 20px rgba(var(--particle-color), 0.3);
}

/* Code Showcase Section */
.code-card {
    background: rgba(12, 14, 24, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 18px;
    overflow: hidden;
    backdrop-filter: blur(12px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

.code-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.8rem 1.2rem;
    background: rgba(0, 0, 0, 0.25);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    flex-wrap: wrap;
    gap: 0.8rem;
}

.window-dots {
    display: flex;
    gap: 6px;
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}
.dot.red { background: #ef4444; }
.dot.yellow { background: #f59e0b; }
.dot.green { background: #10b981; }

.code-title {
    font-size: 0.85rem;
    color: var(--text-sub);
    font-weight: 600;
}

.lang-selector-tabs {
    display: flex;
    gap: 0.3rem;
}

.tab-btn {
    background: transparent;
    border: none;
    color: var(--text-sub);
    font-size: 0.78rem;
    padding: 0.3rem 0.6rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.15s ease;
}

.tab-btn:hover, .tab-btn.active {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-main);
}

.code-body {
    position: relative;
    padding: 1.2rem 1.5rem;
}

pre {
    font-family: var(--font-mono);
    font-size: 0.95rem;
    color: #e2e8f0;
    overflow-x: auto;
    line-height: 1.6;
}

.code-copy-btn {
    position: absolute;
    top: 0.8rem;
    right: 0.8rem;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-sub);
    font-size: 0.75rem;
    padding: 0.35rem 0.7rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.code-copy-btn:hover {
    background: rgba(255, 255, 255, 0.18);
    color: #fff;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(0);
    background: rgba(18, 20, 32, 0.92);
    backdrop-filter: blur(12px);
    border: 1px solid var(--primary-glow);
    color: #fff;
    padding: 0.75rem 1.5rem;
    border-radius: 30px;
    font-size: 0.9rem;
    font-weight: 500;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5), 0 0 15px rgba(var(--particle-color), 0.4);
    z-index: 1000;
    animation: fadeInToast 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.toast[hidden] {
    display: none;
}

/* Footer */
.app-footer {
    position: relative;
    z-index: 5;
    text-align: center;
    padding: 1.5rem;
    font-size: 0.85rem;
    color: var(--text-sub);
    border-top: 1px solid rgba(255, 255, 255, 0.04);
}

/* Keyframes */
@keyframes pulseGlow {
    0% { transform: scale(1); opacity: 0.8; }
    100% { transform: scale(1.3); opacity: 1; }
}

@keyframes fadeInToast {
    from { opacity: 0; transform: translateX(-50%) translateY(20px); }
    to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* Responsive */
@media (max-width: 640px) {
    .app-header {
        padding: 1rem;
    }
    .hero-card {
        padding: 2.5rem 1.2rem;
    }
    .main-title {
        font-size: 3rem;
    }
    .time-badge {
        display: none;
    }
    .action-bar {
        width: 100%;
        flex-direction: column;
    }
    .primary-btn, .secondary-btn {
        width: 100%;
        justify-content: center;
    }
}