/* ===== CSS Variables ===== */
:root {
    --font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;

    /* Colors */
    --bg-gradient-start: #0f0c29;
    --bg-gradient-mid: #302b63;
    --bg-gradient-end: #24243e;

    --glass-bg: rgba(255, 255, 255, 0.08);
    --glass-border: rgba(255, 255, 255, 0.15);
    --glass-shadow: rgba(0, 0, 0, 0.3);

    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-muted: rgba(255, 255, 255, 0.5);

    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-success: #10b981;
    --accent-danger: #ef4444;

    /* Heatmap Colors (GitHub Style Green) */
    --heatmap-0: rgba(255, 255, 255, 0.08);
    --heatmap-1: #0e4429;
    --heatmap-2: #006d32;
    --heatmap-3: #26a641;
    --heatmap-4: #39d353;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
}

/* ===== Reset & Base ===== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-mid), var(--bg-gradient-end));
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* ===== App Container ===== */
.app-container {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--spacing-md);
    min-height: 100vh;
}

/* ===== Header ===== */
.header {
    padding: var(--spacing-lg) 0;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.logo {
    font-size: 1.75rem;
    font-weight: 700;
    background: linear-gradient(135deg, #fff, var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.date-nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.nav-btn {
    width: 36px;
    height: 36px;
    border: none;
    background: var(--glass-bg);
    color: var(--text-primary);
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.25rem;
    transition: var(--transition-fast);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
}

.nav-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: scale(1.05);
}

.current-date {
    font-size: 1.1rem;
    font-weight: 500;
    min-width: 140px;
    text-align: center;
}

/* ===== Header Actions ===== */
.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

/* ===== Sync Button ===== */
.sync-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    cursor: pointer;
    font-size: 0.9rem;
    transition: var(--transition-fast);
}

.sync-btn:hover {
    background: rgba(255, 255, 255, 0.15);
}

.sync-btn.syncing .sync-icon {
    animation: spin 1s linear infinite;
}

.sync-btn.synced {
    border-color: var(--accent-success);
}

.sync-btn.error {
    border-color: var(--accent-danger);
}

.sync-status {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.sync-status.connected {
    color: var(--accent-success);
}

@keyframes spin {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

/* ===== Glass Card ===== */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: 0 8px 32px var(--glass-shadow);
    transition: var(--transition-normal);
}

.glass-card:hover {
    border-color: rgba(255, 255, 255, 0.2);
}

/* ===== Main Content ===== */
.main-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* ===== Section Header ===== */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.section-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
}

/* ===== Buttons ===== */
.add-btn,
.settings-btn {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border: none;
    color: white;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.875rem;
    font-weight: 500;
    font-family: var(--font-family);
    transition: var(--transition-fast);
}

.add-btn:hover,
.settings-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

.btn {
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    font-family: var(--font-family);
    transition: var(--transition-fast);
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: var(--glass-bg);
    color: var(--text-primary);
    border: 1px solid var(--glass-border);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
}

.btn-danger {
    background: var(--accent-danger);
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
}

/* ===== Routine List ===== */
.routine-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    min-height: 100px;
}

.routine-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
    cursor: pointer;
}

.routine-item:hover {
    background: rgba(255, 255, 255, 0.1);
}

.routine-item.completed {
    opacity: 0.6;
}

.routine-item.completed .routine-text {
    text-decoration: line-through;
    color: var(--text-muted);
}

/* Custom Checkbox */
.checkbox-wrapper {
    position: relative;
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

.checkbox-wrapper input {
    position: absolute;
    opacity: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
    z-index: 1;
}

.checkmark {
    position: absolute;
    top: 0;
    left: 0;
    width: 24px;
    height: 24px;
    border: 2px solid var(--glass-border);
    border-radius: 6px;
    background: transparent;
    transition: var(--transition-fast);
}

.checkbox-wrapper input:checked+.checkmark {
    background: linear-gradient(135deg, var(--accent-success), #059669);
    border-color: var(--accent-success);
}

.checkmark::after {
    content: '';
    position: absolute;
    display: none;
    left: 7px;
    top: 3px;
    width: 6px;
    height: 11px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.checkbox-wrapper input:checked+.checkmark::after {
    display: block;
}

.routine-text {
    flex: 1;
    font-size: 1rem;
}

.routine-edit-btn {
    opacity: 0;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: var(--spacing-xs);
    font-size: 1rem;
    transition: var(--transition-fast);
}

.routine-item:hover .routine-edit-btn {
    opacity: 1;
}

.routine-edit-btn:hover {
    color: var(--text-primary);
}

.empty-state {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-muted);
}

/* ===== Progress Bar ===== */
.progress-container {
    margin-top: var(--spacing-md);
}

.progress-label {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
    font-size: 0.9rem;
}

.progress-percent {
    font-weight: 600;
    color: var(--accent-success);
}

.progress-bar {
    height: 12px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 6px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--accent-success), #34d399);
    border-radius: 6px;
    transition: width 0.5s ease;
}

/* ===== Heatmap ===== */
.heatmap-section {
    overflow: hidden;
}

.heatmap-legend {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.legend-boxes {
    display: flex;
    gap: 3px;
}

.legend-box {
    width: 12px;
    height: 12px;
    border-radius: 2px;
}

.level-0 {
    background: var(--heatmap-0);
}

.level-1 {
    background: var(--heatmap-1);
}

.level-2 {
    background: var(--heatmap-2);
}

.level-3 {
    background: var(--heatmap-3);
}

.level-4 {
    background: var(--heatmap-4);
}

.heatmap-container {
    overflow-x: auto;
    padding-bottom: var(--spacing-sm);
}

.heatmap-months {
    display: flex;
    gap: 0;
    margin-left: 32px;
    margin-bottom: var(--spacing-xs);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.heatmap-months span {
    flex: 1;
    min-width: 50px;
}

.heatmap-wrapper {
    display: flex;
    gap: var(--spacing-sm);
}

.heatmap-days {
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    font-size: 0.7rem;
    color: var(--text-muted);
    padding: 2px 0;
    height: 90px;
}

.heatmap-grid {
    display: grid;
    grid-template-rows: repeat(7, 1fr);
    grid-auto-flow: column;
    gap: 3px;
}

.heatmap-cell {
    width: 12px;
    height: 12px;
    border-radius: 2px;
    background: var(--heatmap-0);
    transition: var(--transition-fast);
    cursor: pointer;
}

.heatmap-cell:hover {
    outline: 2px solid rgba(255, 255, 255, 0.5);
    outline-offset: 1px;
}

.heatmap-cell[data-level="1"] {
    background: var(--heatmap-1);
}

.heatmap-cell[data-level="2"] {
    background: var(--heatmap-2);
}

.heatmap-cell[data-level="3"] {
    background: var(--heatmap-3);
}

.heatmap-cell[data-level="4"] {
    background: var(--heatmap-4);
}

/* Heatmap Tooltip */
.heatmap-cell[title] {
    position: relative;
}

/* ===== Calendar Section ===== */
.calendar-container {
    min-height: 300px;
    border-radius: var(--radius-md);
    overflow: hidden;
}

.calendar-placeholder {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 300px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-md);
    color: var(--text-muted);
    text-align: center;
    padding: var(--spacing-lg);
}

.calendar-iframe {
    width: 100%;
    height: 400px;
    border: none;
    border-radius: var(--radius-md);
}

/* ===== Modal ===== */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-normal);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    width: 90%;
    max-width: 400px;
    transform: scale(0.9) translateY(20px);
    transition: var(--transition-normal);
}

.modal-overlay.active .modal {
    transform: scale(1) translateY(0);
}

.modal h3 {
    margin-bottom: var(--spacing-md);
    font-size: 1.25rem;
}

.modal-description {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.modal input {
    width: 100%;
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: var(--font-family);
    margin-bottom: var(--spacing-lg);
    transition: var(--transition-fast);
}

.modal input:focus {
    outline: none;
    border-color: var(--accent-primary);
    background: rgba(255, 255, 255, 0.15);
}

.modal input::placeholder {
    color: var(--text-muted);
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-sm);
}

/* ===== Responsive ===== */
@media (max-width: 600px) {
    .app-container {
        padding: var(--spacing-sm);
    }

    .header-content {
        flex-direction: column;
        text-align: center;
    }

    .logo {
        font-size: 1.5rem;
    }

    .glass-card {
        padding: var(--spacing-md);
    }

    .section-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .heatmap-legend {
        display: none;
    }

    .heatmap-cell {
        width: 10px;
        height: 10px;
    }
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.routine-item {
    animation: fadeIn 0.3s ease;
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}