:root {
    --primary-color: #4ecdc4;
    --secondary-color: #f7f7f7;
    --text-color: #333;
    --border-color: #ddd;
    --today-bg: #fff3cd;
    --selected-bg: #e7f3ff;
    --event-red: #ff6b6b;
    --event-blue: #4ecdc4;
    --event-green: #95e1d3;
    --event-yellow: #ffd93d;
    --event-purple: #c7b3e5;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text-color);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

.header-top {
    position: relative;
    margin-bottom: 15px;
}

header h1 {
    font-size: 2.5em;
    margin: 0;
}

.history-btn {
    position: absolute;
    top: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: 10px 20px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.history-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    border-color: rgba(255, 255, 255, 0.5);
    transform: translateY(-2px);
}

.header-info {
    font-size: 1.1em;
    opacity: 0.9;
}

.mobile-warning {
    color: #ffffff;
    font-weight: bold;
    font-size: 0.95em;
    margin-top: 15px;
    padding: 10px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 6px;
}

.controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
    padding: 20px;
    background: var(--secondary-color);
    flex-wrap: wrap;
}

.nav-button,
.btn-primary,
.btn-secondary,
.btn-danger {
    padding: 10px 15px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1em;
    transition: all 0.3s ease;
}

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

.nav-button:hover {
    background: #3db8aa;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(78, 205, 196, 0.4);
}

.date-selector {
    display: flex;
    gap: 10px;
}

.date-selector select {
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1em;
    background: white;
    cursor: pointer;
}

.btn-primary {
    background: #667eea;
    color: white;
    width: 100%;
}

.btn-primary:hover {
    background: #5568d3;
    transform: translateY(-2px);
}

.btn-secondary {
    background: var(--secondary-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    width: 100%;
}

.btn-secondary:hover {
    background: #e7e7e7;
}

.btn-danger {
    background: #ff6b6b;
    color: white;
    width: 100%;
}

.btn-danger:hover {
    background: #ff5252;
}

main {
    padding: 20px;
}

.calendar-view {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 20px;
}

@media (max-width: 1200px) {
    .calendar-view {
        grid-template-columns: 1fr;
    }
}

.calendar-container {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
}

.calendar-header {
    background: var(--primary-color);
    color: white;
    padding: 15px;
    text-align: center;
    font-size: 1.3em;
    font-weight: bold;
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 1px;
    background: var(--border-color);
    padding: 1px;
}

.day-header {
    background: #f0f0f0;
    padding: 10px;
    text-align: center;
    font-weight: bold;
    font-size: 0.9em;
}

.calendar-day {
    background: white;
    min-height: 80px;
    padding: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
    border: 1px solid var(--border-color);
}

.calendar-day:hover {
    background: #f9f9f9;
    box-shadow: inset 0 0 5px rgba(0, 0, 0, 0.05);
}

.calendar-day.today {
    background: var(--today-bg);
    font-weight: bold;
}

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

.calendar-day.other-month {
    background: #fafafa;
    color: #ccc;
}

.day-number {
    font-weight: bold;
    margin-bottom: 5px;
    font-size: 1.1em;
}

.day-info {
    font-size: 0.75em;
    color: #666;
    margin-bottom: 3px;
}

.day-events {
    font-size: 0.7em;
    max-height: 40px;
    overflow: hidden;
}

.event-dot {
    display: inline-block;
    width: 4px;
    height: 4px;
    border-radius: 50%;
    margin-right: 3px;
    margin-bottom: 2px;
}

.sidebar {
    background: var(--secondary-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow-y: auto;
    max-height: 800px;
}

.sidebar-section {
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-section:last-child {
    border-bottom: none;
}

.sidebar-section h3 {
    margin-bottom: 15px;
    color: var(--primary-color);
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
    font-size: 0.9em;
}

.form-group input[type="text"],
.form-group textarea {
    width: 100%;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-family: inherit;
    font-size: 0.9em;
}

.form-group input[type="text"]:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 5px rgba(78, 205, 196, 0.3);
}

.form-group textarea {
    resize: vertical;
    min-height: 60px;
}

.color-picker {
    display: flex;
    gap: 10px;
}

.color-picker input[type="radio"] {
    display: none;
}

.color-picker label {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all 0.2s ease;
    display: block;
    margin: 0;
}

.color-picker input[type="radio"]:checked + label {
    border-color: #333;
    transform: scale(1.2);
}

.events-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.event-item {
    background: white;
    padding: 12px;
    border-radius: 4px;
    border-left: 4px solid;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: all 0.2s ease;
}

.event-item:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.event-item.red {
    border-left-color: var(--event-red);
}

.event-item.blue {
    border-left-color: var(--event-blue);
}

.event-item.green {
    border-left-color: var(--event-green);
}

.event-item.yellow {
    border-left-color: var(--event-yellow);
}

.event-item.purple {
    border-left-color: var(--event-purple);
}

.event-title {
    font-weight: bold;
    margin-bottom: 5px;
    font-size: 0.9em;
}

.event-date {
    font-size: 0.75em;
    color: #666;
    margin-bottom: 5px;
}

.event-description {
    font-size: 0.8em;
    color: #555;
    margin-bottom: 8px;
}

.event-actions {
    display: flex;
    gap: 5px;
}

.event-actions button {
    flex: 1;
    padding: 4px;
    border: 1px solid var(--border-color);
    background: white;
    border-radius: 3px;
    cursor: pointer;
    font-size: 0.7em;
    transition: all 0.2s ease;
}

.event-actions button:hover {
    background: #f0f0f0;
}

.event-actions .delete-btn:hover {
    background: #ff6b6b;
    color: white;
    border-color: #ff6b6b;
}

.empty-message {
    text-align: center;
    color: #999;
    padding: 20px;
    font-size: 0.9em;
}

.week-indicator {
    position: absolute;
    top: 5px;
    right: 5px;
    font-size: 0.65em;
    color: #999;
    background: #f0f0f0;
    padding: 2px 4px;
    border-radius: 3px;
}