:root {
    /* Light theme colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-card: #ffffff;
    --text-primary: #2c3e50;
    --text-secondary: #6c757d;
    --accent-primary: #3498db;
    --accent-secondary: #2ecc71;
    --accent-danger: #e74c3c;
    --border-color: #e9ecef;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 8px 15px rgba(0, 0, 0, 0.15);
}

[data-theme="dark"] {
    /* Dark theme colors */
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-card: #333333;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --accent-primary: #4fc3f7;
    --accent-secondary: #66bb6a;
    --accent-danger: #ef5350;
    --border-color: #404040;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 8px 15px rgba(0, 0, 0, 0.4);
}

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

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
    z-index: -1;
    pointer-events: none;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem 1rem;
    position: relative;
    z-index: 1;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    flex: 1;
}

.theme-toggle {
    background: none;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: all 0.3s ease;
    background-color: var(--bg-card);
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow);
}

.card {
    background-color: var(--bg-card);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

.card h2 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    text-align: center;
}

.card h3 {
    font-size: 1.4rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

input[type="text"],
input[type="datetime-local"],
input[type="date"],
select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: border-color 0.3s ease;
}

input[type="text"]:focus,
input[type="datetime-local"]:focus,
input[type="date"]:focus,
select:focus {
    outline: none;
    border-color: var(--accent-primary);
}

input[type="color"] {
    width: 60px;
    height: 40px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    background: none;
}

.error-message {
    color: var(--accent-danger);
    font-size: 0.875rem;
    margin-top: 0.25rem;
    min-height: 1.25rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

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

.btn-primary:hover:not(:disabled) {
    background-color: #2980b9;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

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

.btn-secondary:hover:not(:disabled) {
    background-color: #27ae60;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

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

.btn-danger:hover:not(:disabled) {
    background-color: #c0392b;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-outline {
    background-color: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.btn-outline:hover:not(:disabled) {
    background-color: var(--bg-secondary);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* Countdowns List Styles */
.countdowns-container {
    display: grid;
    gap: 1rem;
}

.countdown-item {
    background-color: var(--bg-secondary);
    border-radius: 12px;
    padding: 1.5rem;
    border: 2px solid var(--border-color);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.countdown-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.countdown-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background-color: var(--accent-primary);
}

.countdown-item-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.countdown-item-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.countdown-item-type {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-transform: capitalize;
}

.countdown-item-time {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-primary);
    margin-bottom: 0.5rem;
}

.countdown-item-date {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.countdown-item-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
}

.countdown-item-actions .btn {
    flex: 1;
}

.no-countdowns {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-secondary);
}

.no-countdowns p {
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

/* Countdown Display Styles */
.countdown-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.countdown-type {
    background-color: var(--accent-secondary);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: capitalize;
}

.countdown-timer {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.time-unit {
    text-align: center;
    padding: 1.5rem;
    background-color: var(--bg-secondary);
    border-radius: 12px;
    border: 2px solid var(--border-color);
}

.time-value {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-primary);
    line-height: 1;
}

.time-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-top: 0.5rem;
}

.countdown-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.celebration-card {
    text-align: center;
    animation: celebrationPulse 2s ease-in-out infinite;
}

@keyframes celebrationPulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.02); }
}

.confetti-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 10;
}

.background-controls {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

.file-input {
    display: none;
}

.bg-preview {
    margin-top: 1rem;
    border-radius: 8px;
    overflow: hidden;
    max-width: 300px;
}

.bg-preview img {
    width: 100%;
    height: auto;
    display: block;
}

.toast-container {
    position: fixed;
    top: 2rem;
    right: 2rem;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toast {
    background-color: var(--bg-card);
    color: var(--text-primary);
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--accent-primary);
    animation: toastSlideIn 0.3s ease-out;
    max-width: 300px;
}

@keyframes toastSlideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.hidden {
    display: none !important;
}

.fade-in {
    animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Event Type Icons */
.event-type-icon {
    margin-right: 0.5rem;
    font-size: 1.1rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .card {
        padding: 1.5rem;
    }
    
    .countdown-timer {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }
    
    .time-value {
        font-size: 2rem;
    }
    
    .countdown-actions {
        flex-direction: column;
    }
    
    .background-controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    .toast-container {
        top: 1rem;
        right: 1rem;
        left: 1rem;
    }
    
    .toast {
        max-width: none;
    }
    
    .countdown-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .countdown-item-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .countdown-item-actions {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .countdown-timer {
        grid-template-columns: 1fr;
    }
    
    .time-value {
        font-size: 1.8rem;
    }
}