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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #0f0f23 0%, #1a1a3e 50%, #0d0d1a 100%);
    min-height: 100vh;
    padding: 20px;
    color: #e0e0ff;
}

.seasons-container {
    max-width: 1400px;
    margin: 0 auto;
    background: rgba(20, 20, 40, 0.9);
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #1a1a3e 0%, #0f0f23 100%);
    color: white;
    padding: 30px;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

header h1 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 10px;
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

header .subtitle {
    font-size: 1.1rem;
    opacity: 0.8;
}

main {
    padding: 30px;
}

.canvas-panel {
    background: linear-gradient(135deg, #0a0a1a 0%, #1a1a2e 100%);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 30px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

#mainCanvas {
    width: 100%;
    height: 500px;
    background: radial-gradient(ellipse at center, #1a1a2e 0%, #0a0a1a 100%);
    border-radius: 8px;
    box-shadow: inset 0 2px 10px rgba(0, 0, 0, 0.5);
}

.season-display {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-top: 20px;
    flex-wrap: wrap;
}

.hemisphere-display {
    display: flex;
    align-items: center;
    gap: 10px;
    background: rgba(255, 255, 255, 0.05);
    padding: 10px 20px;
    border-radius: 20px;
}

.hemisphere-label {
    font-size: 0.9rem;
    color: #a0a0ff;
}

.season-badge {
    padding: 5px 15px;
    border-radius: 15px;
    font-weight: 600;
    font-size: 0.9rem;
    background: rgba(255, 255, 255, 0.1);
    color: #e0e0ff;
    transition: all 0.3s ease;
}

.season-badge.summer {
    background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
    color: white;
}

.season-badge.autumn {
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    color: white;
}

.season-badge.winter {
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    color: white;
}

.season-badge.spring {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
}

.controls-panel {
    background: linear-gradient(135deg, #1a1a2e 0%, #0f0f23 100%);
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 30px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.controls-panel h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: #fbbf24;
    margin-bottom: 20px;
}

.controls-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 25px;
}

.control-group {
    background: rgba(255, 255, 255, 0.03);
    padding: 15px;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.control-group label {
    display: block;
    font-weight: 600;
    color: #b0b0ff;
    margin-bottom: 10px;
    font-size: 0.95rem;
}

.control-group label span:last-child {
    color: #fbbf24;
    font-weight: 700;
}

.control-group input[type="range"] {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: rgba(255, 255, 255, 0.1);
    outline: none;
    -webkit-appearance: none;
}

.control-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: #fbbf24;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(251, 191, 36, 0.4);
}

.control-group input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: #fbbf24;
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 8px rgba(251, 191, 36, 0.4);
}

.checkbox-input {
    width: 24px;
    height: 24px;
    cursor: pointer;
    accent-color: #fbbf24;
}

.button-group {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.control-button {
    padding: 12px 30px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
}

.control-button.start {
    background: #10b981;
    color: white;
}

.control-button.start:hover {
    background: #059669;
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(16, 185, 129, 0.3);
}

.control-button.pause {
    background: #f59e0b;
    color: white;
}

.control-button.pause:hover {
    background: #d97706;
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(245, 158, 11, 0.3);
}

.control-button.reset {
    background: #6b7280;
    color: white;
}

.control-button.reset:hover {
    background: #4b5563;
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(107, 114, 128, 0.3);
}

.info-display {
    text-align: center;
    font-size: 1.1rem;
    color: #fbbf24;
    font-weight: 600;
    padding: 15px;
    background: rgba(251, 191, 36, 0.1);
    border-radius: 8px;
}

.formulas-section {
    background: rgba(255, 255, 255, 0.03);
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 30px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.formulas-section h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: #fbbf24;
    margin-bottom: 15px;
}

.formula-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.formula-item {
    padding: 12px 15px;
    background: rgba(251, 191, 36, 0.08);
    border-radius: 6px;
    border-left: 3px solid #fbbf24;
}

.formula {
    font-family: 'Times New Roman', serif;
    font-size: 1rem;
    color: #e0e0ff;
}

.explanation {
    background: rgba(255, 255, 255, 0.02);
    padding: 25px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.explanation h2 {
    font-size: 1.6rem;
    font-weight: 700;
    color: #fbbf24;
    margin-bottom: 20px;
}

.explanation p {
    line-height: 1.8;
    color: #b0b0e0;
    margin-bottom: 15px;
    font-size: 1rem;
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    header h1 {
        font-size: 1.6rem;
    }

    header .subtitle {
        font-size: 0.95rem;
    }

    main {
        padding: 15px;
    }

    .controls-grid {
        grid-template-columns: 1fr;
    }

    .button-group {
        flex-direction: column;
    }

    .control-button {
        width: 100%;
    }

    #mainCanvas {
        height: 350px;
    }

    .season-display {
        gap: 20px;
    }
}