:root {
    --primary: #4CAF50;
    --primary-dark: #388E3C;
    --secondary: #8BC34A;
    --accent: #FF9800;
    --bg-dark: #121212;
    --bg-card: #181818;
    --bg-card-hover: #232323;
    --text-primary: #FFFFFF;
    --text-secondary: #B3B3B3;
    --border-color: #282828;
    --success: #1DB954;
    --error: #E74C3C;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.navbar {
    background: var(--bg-card);
    padding: 0 24px;
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    transition: all 0.3s;
}

.nav-links a:hover {
    color: var(--text-primary);
    background: var(--bg-card-hover);
}

.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 24px;
}

.footer {
    text-align: center;
    padding: 24px;
    color: var(--text-secondary);
    font-size: 0.85rem;
    border-top: 1px solid var(--border-color);
    margin-top: 40px;
}

/* Auth Page */
.auth-container {
    max-width: 400px;
    margin: 60px auto;
    padding: 40px;
    background: var(--bg-card);
    border-radius: 12px;
}

.auth-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
}

.auth-tab {
    flex: 1;
    padding: 12px;
    background: var(--bg-dark);
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s;
}

.auth-tab.active {
    background: var(--primary);
    color: white;
}

.auth-form {
    display: none;
}

.auth-form.active {
    display: block;
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.form-group input, .form-group select {
    width: 100%;
    padding: 12px 16px;
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus, .form-group select:focus {
    outline: none;
    border-color: var(--primary);
}

.btn-primary {
    width: 100%;
    padding: 14px;
    background: var(--primary);
    border: none;
    border-radius: 8px;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

/* Dashboard */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    margin-top: 24px;
}

.card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 24px;
    transition: transform 0.3s;
}

.card:hover {
    transform: translateY(-4px);
}

.card-title {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.card-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
}

.card-unit {
    font-size: 1rem;
    color: var(--text-secondary);
}

/* Profile Form */
.profile-container {
    max-width: 600px;
    margin: 0 auto;
    background: var(--bg-card);
    border-radius: 12px;
    padding: 32px;
}

.profile-form {
    display: grid;
    gap: 20px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.radio-group {
    display: flex;
    gap: 16px;
}

.radio-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.radio-item input[type="radio"] {
    width: 18px;
    height: 18px;
    accent-color: var(--primary);
}

/* Week Plan */
.week-plan {
    margin-top: 24px;
}

.day-section {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 16px;
}

.day-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.day-name {
    font-size: 1.2rem;
    font-weight: 600;
}

.day-date {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.meal-section {
    margin-bottom: 16px;
}

.meal-type {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.meal-type .emoji {
    font-size: 1.2rem;
}

.recipe-options {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.recipe-chip {
    padding: 8px 16px;
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.3s;
}

.recipe-chip:hover {
    border-color: var(--primary);
}

.recipe-chip.selected {
    background: var(--primary);
    border-color: var(--primary);
}

.recipe-chip .calories {
    color: var(--accent);
    font-size: 0.8rem;
    margin-left: 8px;
}

/* Weight Log */
.weight-chart {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 24px;
}

.weight-list {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 24px;
}

.weight-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
}

.weight-item:last-child {
    border-bottom: none;
}

.weight-date {
    color: var(--text-secondary);
}

.weight-value {
    font-size: 1.2rem;
    font-weight: 600;
}

.weight-change {
    font-size: 0.85rem;
}

.weight-change.positive {
    color: var(--error);
}

.weight-change.negative {
    color: var(--success);
}

/* Food Log */
.food-log-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.date-nav {
    display: flex;
    align-items: center;
    gap: 16px;
}

.date-nav button {
    background: var(--bg-card);
    border: none;
    color: var(--text-primary);
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
}

.food-item {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 16px;
    margin-bottom: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.food-info h4 {
    margin-bottom: 4px;
}

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

.food-calories {
    text-align: right;
}

.food-calories .value {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--accent);
}

.food-calories .unit {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* Alert */
.alert {
    padding: 16px;
    border-radius: 8px;
    margin-bottom: 16px;
}

.alert-success {
    background: rgba(29, 185, 84, 0.2);
    color: var(--success);
}

.alert-error {
    background: rgba(231, 76, 60, 0.2);
    color: var(--error);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 32px;
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
}

.recipe-detail h3 {
    color: var(--primary);
    margin-bottom: 12px;
}

.recipe-detail p {
    color: var(--text-secondary);
    margin-bottom: 8px;
}

@media (max-width: 768px) {
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .nav-links {
        display: none;
    }
}