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

:root {
    --primary-color: #8B4513;
    --primary-light: #A0522D;
    --primary-dark: #654321;
    --accent-color: #D2691E;
    --background: #FFF8F0;
    --card-background: #FFFFFF;
    --text-primary: #2C2C2C;
    --text-secondary: #666666;
    --border-color: #E5D4C1;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #FFF8F0 0%, #F5E6D3 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    animation: fadeIn 0.6s ease-in;
}

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

header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
}

h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 10px;
    font-weight: 700;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.card {
    background: var(--card-background);
    border-radius: 20px;
    padding: 30px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.input-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

label {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.label-text {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1rem;
}

.label-hint {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Coffee Presets */
.coffee-presets {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 12px;
    margin-top: 10px;
}

.preset-btn {
    background: linear-gradient(135deg, #FFFFFF 0%, #F8F8F8 100%);
    border: 2px solid var(--border-color);
    border-radius: 16px;
    padding: 12px 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    min-height: 100px;
    position: relative;
    overflow: hidden;
}

.preset-btn:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 20px rgba(139, 69, 19, 0.2);
    border-color: var(--accent-color);
}

.preset-btn:active {
    transform: translateY(-2px);
}

.preset-btn.selected {
    background: linear-gradient(135deg, var(--accent-color) 0%, var(--primary-color) 100%);
    border-color: var(--primary-dark);
    color: white;
    box-shadow: 0 4px 15px rgba(139, 69, 19, 0.3);
}

.preset-btn.selected .preset-name,
.preset-btn.selected .preset-caffeine {
    color: white;
}

.preset-icon {
    font-size: 2rem;
    line-height: 1;
}

.preset-name {
    font-size: 0.75rem;
    font-weight: 600;
    text-align: center;
    line-height: 1.2;
    color: var(--text-primary);
}

.preset-caffeine {
    font-size: 0.7rem;
    color: var(--accent-color);
    font-weight: 700;
}

input[type="number"],
input[type="time"] {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: #FAFAFA;
}

input[type="number"]:focus,
input[type="time"]:focus {
    outline: none;
    border-color: var(--accent-color);
    background: white;
    transform: scale(1.02);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    padding: 16px 32px;
    border: none;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(139, 69, 19, 0.3);
    margin-top: 10px;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(139, 69, 19, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.result-section {
    animation: slideIn 0.5s ease-out;
}

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

.hidden {
    display: none;
}

h2 {
    color: var(--primary-color);
    font-size: 1.5rem;
    margin-bottom: 20px;
    font-weight: 600;
}

.current-caffeine {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.caffeine-value {
    display: flex;
    align-items: baseline;
    gap: 10px;
}

.big-number {
    font-size: 4rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1;
}

.unit {
    font-size: 1.5rem;
    color: var(--text-secondary);
}

.caffeine-percentage {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.progress-bar {
    width: 100%;
    height: 30px;
    background: #F0F0F0;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1);
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-color) 0%, var(--primary-color) 100%);
    border-radius: 15px;
    transition: width 0.5s ease;
    box-shadow: 0 2px 8px rgba(139, 69, 19, 0.3);
}

.percentage-text {
    text-align: center;
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary-color);
}

.timeline {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.timeline-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background: linear-gradient(90deg, #FFF8F0 0%, #FAFAFA 100%);
    border-radius: 12px;
    border-left: 4px solid var(--accent-color);
    transition: all 0.3s ease;
}

.timeline-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow);
}

.timeline-time {
    font-weight: 600;
    color: var(--primary-color);
    font-size: 1.1rem;
}

.timeline-amount {
    font-size: 1.1rem;
    color: var(--text-primary);
}

.timeline-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-left: 10px;
}

.info-card {
    background: linear-gradient(135deg, #FFF8F0 0%, #FFE4B5 100%);
    border-radius: 20px;
    padding: 25px;
    margin-bottom: 20px;
    border: 2px solid var(--border-color);
}

.info-card h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.info-card ul {
    list-style: none;
    padding: 0;
}

.info-card li {
    padding: 8px 0;
    padding-left: 25px;
    position: relative;
    color: var(--text-primary);
}

.info-card li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-weight: bold;
}

footer {
    text-align: center;
    padding: 30px 20px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

canvas {
    max-width: 100%;
    height: auto !important;
}

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

    h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .card {
        padding: 20px;
        border-radius: 15px;
    }

    .coffee-presets {
        grid-template-columns: repeat(3, 1fr);
    }

    .big-number {
        font-size: 3rem;
    }

    .unit {
        font-size: 1.2rem;
    }

    .timeline-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .timeline-label {
        margin-left: 0;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.75rem;
    }

    .coffee-presets {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .preset-btn {
        padding: 10px 6px;
        min-height: 95px;
    }

    .preset-icon {
        font-size: 1.8rem;
    }

    .preset-name {
        font-size: 0.7rem;
    }

    .preset-caffeine {
        font-size: 0.65rem;
    }

    .big-number {
        font-size: 2.5rem;
    }

    .btn-primary {
        padding: 14px 28px;
        font-size: 1rem;
    }

    .card {
        padding: 15px;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --background: #1A1A1A;
        --card-background: #2C2C2C;
        --text-primary: #E5E5E5;
        --text-secondary: #A0A0A0;
        --border-color: #3C3C3C;
    }

    body {
        background: linear-gradient(135deg, #1A1A1A 0%, #2C2C2C 100%);
    }

    input[type="number"],
    input[type="time"] {
        background: #3C3C3C;
        color: var(--text-primary);
    }

    input[type="number"]:focus,
    input[type="time"]:focus {
        background: #4C4C4C;
    }

    .progress-bar {
        background: #3C3C3C;
    }

    .timeline-item {
        background: linear-gradient(90deg, #2C2C2C 0%, #3C3C3C 100%);
    }

    .info-card {
        background: linear-gradient(135deg, #2C2C2C 0%, #3C2C1C 100%);
    }

    .preset-btn {
        background: linear-gradient(135deg, #3C3C3C 0%, #2C2C2C 100%);
        border-color: #4C4C4C;
    }

    .preset-btn:hover {
        border-color: var(--accent-color);
        background: linear-gradient(135deg, #4C4C4C 0%, #3C3C3C 100%);
    }

    .preset-btn .preset-name {
        color: var(--text-primary);
    }
}