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

:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-color: #1f2937;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --complete-bg: #d1fae5;
    --partial-bg: #fef3c7;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Navbar */
.navbar {
    background: var(--card-bg);
    padding: 15px 20px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-brand a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: bold;
    font-size: 1.2rem;
}

.nav-brand {
    color: var(--primary-color);
    font-weight: bold;
    font-size: 1.2rem;
}

.nav-date {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    font-weight: 500;
    color: var(--text-muted);
}

.nav-links {
    display: flex;
    gap: 20px;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--primary-color);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 10px 20px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    text-decoration: none;
    font-size: 1rem;
    transition: background-color 0.2s, transform 0.1s;
}

.btn:hover {
    transform: translateY(-1px);
}

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

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

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

.btn-small {
    padding: 10px 16px;
    font-size: 0.9rem;
    height: 42px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-nav {
    background: var(--border-color);
    color: var(--text-color);
}

.btn-nav:hover {
    background: var(--border-color);
    filter: brightness(0.95);
}

/* Alerts */
.alert {
    padding: 12px 16px;
    border-radius: 6px;
    margin-bottom: 20px;
}

.alert-success {
    background: var(--complete-bg);
    color: #065f46;
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
}

.alert-warning {
    background: #fef3c7;
    color: #92400e;
}

.alert-info {
    background: #dbeafe;
    color: #1e40af;
}

/* Auth pages */
.auth-container {
    max-width: 400px;
    margin: 60px auto;
    background: var(--card-bg);
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.auth-container h1 {
    text-align: center;
    margin-bottom: 25px;
    color: var(--primary-color);
}

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

.form-group {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.form-group label {
    font-weight: 500;
    color: var(--text-color);
}

.form-group input[type="text"],
.form-group input[type="password"],
.form-group input[type="number"],
.form-group input[type="email"] {
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

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

.form-group.checkbox {
    flex-direction: row;
    align-items: center;
}

.form-group.checkbox input {
    margin-right: 8px;
}

.auth-link {
    text-align: center;
    margin-top: 20px;
    color: var(--text-muted);
}

.auth-link a {
    color: var(--primary-color);
}

/* Dashboard */
.dashboard {
    max-width: 900px;
    margin: 0 auto;
}

.dashboard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 15px;
}

.dashboard-header h1 {
    color: var(--text-color);
}

.status-badge {
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: 500;
    font-size: 0.9rem;
}

.status-complete {
    background: var(--complete-bg);
    color: #065f46;
}

.status-pending {
    background: var(--partial-bg);
    color: #92400e;
}

/* Exercises Grid */
.exercises-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.exercise-card {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.2s, box-shadow 0.2s;
    border-left: 4px solid var(--border-color);
}

.exercise-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.exercise-card.completed {
    border-left-color: var(--success-color);
}

.exercise-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.exercise-header h3 {
    color: var(--text-color);
}

.checkmark {
    color: var(--success-color);
    font-size: 1.5rem;
    font-weight: bold;
}

/* Progress Bar */
.progress-container {
    margin-bottom: 15px;
}

.progress-bar {
    height: 10px;
    background: var(--border-color);
    border-radius: 5px;
    overflow: hidden;
    margin-bottom: 8px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
    transition: width 0.3s ease;
}

.progress-text {
    display: flex;
    justify-content: center;
    gap: 5px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.current-count {
    font-weight: bold;
    color: var(--primary-color);
}

/* Log Form */
.log-form {
    margin-top: 15px;
}

.input-group {
    display: flex;
    gap: 10px;
    align-items: center;
}

.input-group input[type="number"] {
    width: 80px;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
}

.input-group input[type="number"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-muted);
}

.empty-state p {
    margin-bottom: 20px;
}

/* Admin Panel */
.admin-panel {
    max-width: 1000px;
    margin: 0 auto;
}

.admin-panel h1 {
    margin-bottom: 10px;
    color: var(--primary-color);
}

.page-description {
    color: var(--text-muted);
    margin-bottom: 30px;
}

.add-exercise-form,
.add-user-form {
    background: var(--card-bg);
    padding: 25px;
    border-radius: 12px;
    margin-bottom: 30px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.add-exercise-form h2,
.add-user-form h2 {
    margin-bottom: 20px;
    font-size: 1.2rem;
}

.form-row {
    display: flex;
    gap: 15px;
    align-items: flex-end;
    flex-wrap: wrap;
}

.form-row .form-group {
    flex: 1;
    min-width: 200px;
}

.form-row .form-button {
    flex: auto;
}

/* Exercises Table */
.exercises-list,
.users-list {
    background: var(--card-bg);
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.exercises-list h2,
.users-list h2 {
    margin-bottom: 20px;
    font-size: 1.2rem;
}

.exercises-table {
    width: 100%;
    border-collapse: collapse;
}

.exercises-table th,
.exercises-table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.exercises-table th {
    background: var(--bg-color);
    font-weight: 600;
}

.exercises-table tr:hover {
    background: var(--bg-color);
}

/* Badges */
.badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 500;
}

.badge-admin {
    background: var(--primary-color);
    color: white;
}

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

/* Calendar */
.calendar-page {
    max-width: 1000px;
    margin: 0 auto;
}

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

.calendar-header h1 {
    min-width: 200px;
    text-align: center;
}

.calendar-legend {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.legend-color {
    width: 20px;
    height: 20px;
    border-radius: 4px;
}

.legend-color.complete {
    background: var(--complete-bg);
    border: 2px solid var(--success-color);
}

.legend-color.partial {
    background: var(--partial-bg);
    border: 2px solid var(--warning-color);
}

.legend-color.empty {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
}

/* Calendar Grid */
.calendar-grid {
    background: var(--card-bg);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.calendar-weekdays {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    background: var(--bg-color);
    font-weight: 600;
}

.calendar-weekdays div {
    padding: 12px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.calendar-days {
    display: flex;
    flex-direction: column;
}

.calendar-week {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
}

.calendar-day {
    min-height: 100px;
    padding: 8px;
    border: 1px solid var(--border-color);
    position: relative;
    cursor: pointer;
    transition: background 0.2s;
}

.calendar-day:hover {
    background: var(--bg-color);
}

.calendar-day.empty {
    background: var(--bg-color);
    cursor: default;
}

.calendar-day.complete {
    background: var(--complete-bg);
}

.calendar-day.partial {
    background: var(--partial-bg);
}

.calendar-day.today {
    border: 2px solid var(--primary-color);
}

.day-number {
    font-weight: 600;
    font-size: 0.9rem;
}

.day-details {
    margin-top: 8px;
    font-size: 0.75rem;
    max-height: 60px;
    overflow-y: auto;
}

.log-item {
    padding: 2px 0;
    color: var(--text-muted);
}

.log-item.done {
    color: var(--success-color);
    font-weight: 500;
}

.calendar-footer {
    text-align: center;
    margin-top: 20px;
}

/* Share Page */
.share-page {
    max-width: 600px;
    margin: 0 auto;
}

.share-page h1 {
    margin-bottom: 20px;
    color: var(--primary-color);
}

.share-info {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.share-link-container {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.share-link-container label {
    display: block;
    margin-bottom: 10px;
    font-weight: 500;
}

.share-input-group {
    display: flex;
    gap: 10px;
}

.share-input-group input {
    flex: 1;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.9rem;
    background: var(--bg-color);
}

.copy-message {
    color: var(--success-color);
    margin-top: 10px;
    font-weight: 500;
    opacity: 0;
    transition: opacity 0.3s;
}

.copy-message.show {
    opacity: 1;
}

.share-preview {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.share-preview h2 {
    margin-bottom: 15px;
    font-size: 1.1rem;
}

.share-preview ul {
    margin-left: 20px;
    margin-bottom: 15px;
}

.share-preview li {
    margin-bottom: 8px;
}

.share-preview .warning {
    color: var(--warning-color);
    font-size: 0.9rem;
}

/* Public Page */
.public-page {
    background: var(--bg-color);
}

.public-page .navbar {
    background: var(--primary-color);
}

.public-page .nav-brand {
    color: white;
}

.exercises-summary {
    margin-top: 30px;
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.exercises-summary h2 {
    margin-bottom: 15px;
}

.exercises-list-public {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 10px;
}

.exercises-list-public li {
    padding: 10px;
    background: var(--bg-color);
    border-radius: 6px;
}

/* Responsive */
@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        gap: 15px;
        position: relative;
    }

    .nav-date {
        position: static;
        transform: none;
        order: 3;
    }

    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
    }

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

    .calendar-header {
        flex-direction: column;
    }

    .calendar-day {
        min-height: 60px;
        padding: 4px;
    }

    .day-details {
        display: none;
    }

    .form-row {
        flex-direction: column;
    }

    .form-row .form-group {
        width: 100%;
    }

    .share-input-group {
        flex-direction: column;
    }
}