:root {
    --bg-color: #0f172a;
    --card-color: #1e293b;
    --accent-color: #10b981;
    --accent-hover: #059669;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --danger: #ef4444;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Inter', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    padding-bottom: 70px;
}

.app-header {
    background-color: var(--card-color);
    padding: 1rem;
    text-align: center;
    position: sticky;
    top: 0;
    z-index: 10;
    border-bottom: 1px solid var(--border-color);
}

.app-header h1 {
    font-size: 1.25rem;
    color: var(--accent-color);
}

.app-main {
    padding: 1rem;
    max-width: 800px;
    margin: 0 auto;
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s ease-in-out;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

h2 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.section-subtitle {
    margin: 1.5rem 0 1rem;
    font-size: 1.2rem;
    color: var(--accent-color);
}

.card {
    background-color: var(--card-color);
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 1rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--border-color);
}

.form-group {
    margin-bottom: 1rem;
    flex: 1;
}

.form-group label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

input[type="text"], input[type="number"], textarea {
    width: 100%;
    padding: 0.75rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-color);
    color: var(--text-main);
    font-size: 1rem;
}

input:focus, textarea:focus {
    outline: none;
    border-color: var(--accent-color);
}

textarea {
    resize: vertical;
    min-height: 80px;
}

.row {
    display: flex;
    gap: 1rem;
}

.align-center {
    align-items: center;
}

.form-checkbox {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0.5rem;
}

.form-checkbox input {
    width: 18px;
    height: 18px;
    accent-color: var(--accent-color);
}

button {
    cursor: pointer;
    border: none;
    font-weight: 600;
    transition: background-color 0.2s;
}

.btn-primary, .btn-secondary, .btn-danger {
    width: 100%;
    padding: 0.75rem;
    border-radius: 8px;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--accent-color);
    color: var(--bg-color);
}

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

.btn-secondary {
    background-color: transparent;
    border: 1px solid var(--accent-color);
    color: var(--accent-color);
}

.btn-danger {
    background-color: transparent;
    border: 1px solid var(--danger);
    color: var(--danger);
}

.large-btn {
    padding: 1rem;
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.action-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.flex-form {
    display: flex;
    gap: 0.5rem;
}

.btn-icon {
    background-color: var(--accent-color);
    color: var(--bg-color);
    border-radius: 8px;
    width: 45px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.items-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.record-item, .routine-item, .session-item {
    background-color: var(--card-color);
    border-radius: 10px;
    padding: 1rem;
    border-left: 4px solid var(--accent-color);
}

.item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.item-title {
    font-weight: 700;
    font-size: 1.1rem;
}

.item-date {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.item-stats {
    display: flex;
    gap: 1rem;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.item-stat strong {
    color: var(--accent-color);
}

.routine-alt {
    margin-top: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-muted);
    font-style: italic;
    background: rgba(255,255,255,0.05);
    padding: 0.5rem;
    border-radius: 6px;
}

.meal-list {
    list-style: none;
    margin-top: 1rem;
}

.meal-list li {
    background-color: rgba(255,255,255,0.05);
    padding: 0.75rem;
    border-radius: 8px;
    margin-bottom: 0.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.delete-btn {
    background: none;
    color: var(--danger);
    font-size: 1.2rem;
    padding: 0 0.5rem;
}

.session-log {
    margin-top: 1rem;
    background: var(--bg-color);
    border-radius: 8px;
    padding: 1rem;
}

.session-log p {
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background-color: var(--card-color);
    display: flex;
    justify-content: space-around;
    padding: 0.75rem 0;
    border-top: 1px solid var(--border-color);
    z-index: 100;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.75rem;
    gap: 0.3rem;
    transition: color 0.2s;
}

.nav-item i {
    font-size: 1.25rem;
}

.nav-item.active {
    color: var(--accent-color);
}

.hidden {
    display: none !important;
}