/* ========================================
   CSS Variables & Reset
======================================== */
:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a25;
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --text-muted: #606070;
    --accent-blue: #4a90d9;
    --accent-gold: #d4af37;
    --glass-bg: rgba(30, 30, 45, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --shadow-dark: rgba(0, 0, 0, 0.5);
    --gradient-shine: linear-gradient(135deg, rgba(255,255,255,0.1) 0%, transparent 50%);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

/* ========================================
   Layout
======================================== */
.container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background: 
        radial-gradient(ellipse at 20% 80%, rgba(74, 144, 217, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(212, 175, 55, 0.05) 0%, transparent 50%),
        var(--bg-primary);
}

/* ========================================
   Header
======================================== */
.header {
    padding: 20px 40px;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    border-bottom: 1px solid var(--glass-border);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.logo {
    font-size: 18px;
    font-weight: 500;
    color: var(--text-primary);
    letter-spacing: 0.5px;
}

/* ========================================
   Main Content
======================================== */
.main-content {
    flex: 1;
    display: flex;
    padding: 30px;
    gap: 30px;
}

/* ========================================
   Canvas Container
======================================== */
.canvas-container {
    flex: 1;
    position: relative;
    background: var(--bg-secondary);
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid var(--glass-border);
    box-shadow: 
        0 20px 60px var(--shadow-dark),
        inset 0 1px 0 rgba(255,255,255,0.05);
}

#three-canvas {
    width: 100%;
    height: 100%;
    min-height: 600px;
}

#three-canvas canvas {
    width: 100% !important;
    height: 100% !important;
}

/* View Toggle Button */
.view-toggle {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
}

.view-btn {
    padding: 12px 40px;
    background: linear-gradient(135deg, var(--accent-blue), #3a70b9);
    border: none;
    border-radius: 30px;
    color: white;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 
        0 4px 20px rgba(74, 144, 217, 0.4),
        0 0 0 1px rgba(255,255,255,0.1) inset;
}

.view-btn:hover {
    transform: translateY(-2px);
    box-shadow: 
        0 6px 30px rgba(74, 144, 217, 0.5),
        0 0 0 1px rgba(255,255,255,0.2) inset;
}

.view-btn.active {
    background: linear-gradient(135deg, var(--accent-blue), #3a70b9);
}

/* ========================================
   Control Panel
======================================== */
.control-panel {
    width: 280px;
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.panel-section {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 20px;
    box-shadow: 0 10px 40px var(--shadow-dark);
}

.section-title {
    display: flex;
    gap: 15px;
    margin-bottom: 12px;
    flex-wrap: wrap;
}

.title-text {
    color: var(--accent-gold);
    font-size: 15px;
    font-weight: 600;
}

.title-sub {
    color: var(--text-secondary);
    font-size: 15px;
    font-weight: 400;
}

.section-hint {
    font-size: 12px;
    color: var(--text-muted);
    line-height: 1.6;
}

/* Part Selector */
.part-selector {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 15px;
}

.part-btn {
    flex: 1;
    min-width: calc(50% - 5px);
    padding: 12px 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.part-btn:hover {
    background: rgba(74, 144, 217, 0.1);
    border-color: var(--accent-blue);
    color: var(--text-primary);
}

.part-btn.active {
    background: linear-gradient(135deg, rgba(212, 175, 55, 0.2), rgba(212, 175, 55, 0.1));
    border-color: var(--accent-gold);
    color: var(--accent-gold);
    box-shadow: 0 0 20px rgba(212, 175, 55, 0.2);
}

/* Color Section */
.color-section {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 20px;
}

.color-title {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 15px;
}

.color-palette {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}

.color-btn {
    width: 100%;
    aspect-ratio: 1;
    border-radius: 12px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.color-btn::after {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-shine);
    pointer-events: none;
}

.color-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 4px 20px rgba(0,0,0,0.4);
}

.color-btn.selected {
    border-color: var(--accent-gold);
    box-shadow: 
        0 0 0 2px var(--bg-primary),
        0 0 0 4px var(--accent-gold),
        0 4px 20px rgba(212, 175, 55, 0.3);
}

/* Reset Button */
.reset-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 20px;
    background: var(--bg-tertiary);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.reset-btn:hover {
    background: rgba(255, 100, 100, 0.1);
    border-color: rgba(255, 100, 100, 0.3);
    color: #ff6b6b;
}

.reset-btn svg {
    transition: transform 0.3s ease;
}

.reset-btn:hover svg {
    transform: rotate(-180deg);
}

/* ========================================
   Responsive Design
======================================== */
@media (max-width: 900px) {
    .main-content {
        flex-direction: column;
        padding: 20px;
    }

    .control-panel {
        width: 100%;
    }

    #three-canvas {
        min-height: 400px;
    }

    .color-palette {
        grid-template-columns: repeat(8, 1fr);
    }
}

@media (max-width: 600px) {
    .header {
        padding: 15px 20px;
    }

    .section-title {
        flex-direction: column;
        gap: 5px;
    }

    .color-palette {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* ========================================
   Animations
======================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.control-panel > * {
    animation: fadeIn 0.5s ease forwards;
}

.control-panel > *:nth-child(1) { animation-delay: 0.1s; }
.control-panel > *:nth-child(2) { animation-delay: 0.2s; }
.control-panel > *:nth-child(3) { animation-delay: 0.3s; }
.control-panel > *:nth-child(4) { animation-delay: 0.4s; }

/* Loading indicator */
.loading {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: var(--text-secondary);
    font-size: 14px;
}

.loading::after {
    content: '';
    display: inline-block;
    width: 20px;
    height: 20px;
    margin-left: 10px;
    border: 2px solid var(--glass-border);
    border-top-color: var(--accent-blue);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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