/* Base Styles */
:root {
    --primary-color: #4361ee;
    --secondary-color: #3f37c9;
    --accent-color: #4895ef;
    --light-color: #f8f9fa;
    --dark-color: #212529;
    --success-color: #4bb543;
    --warning-color: #f0ad4e;
    --danger-color: #d9534f;
    --gray-color: #6c757d;
    --light-gray: #e9ecef;
    --border-radius: 8px;
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background-color: #f5f7fa;
}

/* Layout */
.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

.content-wrapper {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin: 20px 0;
}

.sidebar {
    flex: 1;
    min-width: 250px;
    max-width: 300px;
}

.main-content {
    flex: 3;
    min-width: 300px;
}

/* Header */
.app-header {
    text-align: center;
    padding: 30px 0;
    margin-bottom: 20px;
}

.app-header h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--gray-color);
}

/* Tab Navigation */
.tab-nav {
    display: flex;
    border-bottom: 1px solid var(--light-gray);
    margin-bottom: 20px;
}

.tab-btn {
    padding: 12px 20px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    color: var(--gray-color);
    position: relative;
    transition: var(--transition);
}

.tab-btn.active {
    color: var(--primary-color);
    font-weight: 600;
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* Time Display */
.time-display {
    font-size: 3.5rem;
    font-weight: 300;
    text-align: center;
    margin: 20px 0;
    font-family: 'Courier New', monospace;
    color: var(--dark-color);
}

/* Input Groups */
.time-input {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin: 20px 0;
}

.input-group {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.input-group label {
    font-size: 0.9rem;
    color: var(--gray-color);
    margin-bottom: 5px;
}

.input-group input {
    width: 80px;
    padding: 8px 12px;
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
    font-size: 1.2rem;
    text-align: center;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    gap: 8px;
}

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

.btn-primary:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
}

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

.btn-secondary:hover {
    background-color: #5a6268;
    transform: translateY(-2px);
}

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

.btn-outline:hover {
    background-color: var(--light-gray);
    transform: translateY(-2px);
}

.btn-action {
    background-color: var(--light-color);
    color: var(--dark-color);
    border: 1px solid var(--light-gray);
}

.btn-action:hover {
    background-color: #e2e6ea;
    transform: translateY(-2px);
}

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

.control-buttons {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.action-buttons {
    display: flex;
    gap: 10px;
    margin-top: 15px;
    flex-wrap: wrap;
}

/* Laps Section */
.laps-section {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid var(--light-gray);
}

.laps-section h3 {
    margin-bottom: 15px;
    text-align: center;
}

.laps-container {
    max-height: 300px;
    overflow-y: auto;
    padding: 10px;
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.lap-item {
    display: flex;
    justify-content: space-between;
    padding: 8px 12px;
    border-bottom: 1px solid var(--light-gray);
    font-family: 'Courier New', monospace;
}

.lap-item:last-child {
    border-bottom: none;
}

.lap-number {
    font-weight: 600;
    color: var(--primary-color);
}

/* Timer Options */
.timer-options {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 20px;
}

.option {
    display: flex;
    align-items: center;
    gap: 5px;
}

.option input[type="checkbox"] {
    width: 16px;
    height: 16px;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: var(--success-color);
    color: white;
    padding: 12px 20px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    transform: translateY(100px);
    opacity: 0;
    transition: var(--transition);
    z-index: 1000;
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}

/* Alarm Flash */
.alarm-flash {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0.9);
    z-index: 999;
    display: none;
    animation: flash 0.5s infinite alternate;
}

@keyframes flash {
    from { background-color: rgba(255, 255, 255, 0.9); }
    to { background-color: rgba(255, 230, 230, 0.9); }
}

/* Ad Containers */
.ad-container {
    background-color: var(--light-gray);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.ad-placeholder {
    padding: 20px;
    color: var(--gray-color);
    text-align: center;
}

.top-banner {
    height: 90px;
    margin-bottom: 20px;
}

.sidebar-ad {
    height: 250px;
}

.in-content-ad {
    height: 100px;
    margin-bottom: 20px;
}

/* Article Container */
.article-container {
    background-color: white;
    border-radius: var(--border-radius);
    padding: 20px;
    margin-top: 20px;
    box-shadow: var(--box-shadow);
}

.article-container h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.article-container h4 {
    color: var(--secondary-color);
    margin: 15px 0 10px;
    font-size: 1.1rem;
}

.article-container p, .article-container ul, .article-container ol {
    margin-bottom: 15px;
    color: var(--dark-color);
}

.article-container ul, .article-container ol {
    padding-left: 20px;
}

/* Footer */
.app-footer {
    text-align: center;
    padding: 20px 0;
    margin-top: 40px;
    color: var(--gray-color);
    font-size: 0.9rem;
    border-top: 1px solid var(--light-gray);
}

/* Responsive Design */
@media (max-width: 768px) {
    .content-wrapper {
        flex-direction: column;
    }

    .sidebar {
        max-width: 100%;
    }

    .app-header h1 {
        font-size: 2rem;
    }

    .time-display {
        font-size: 2.5rem;
    }

    .control-buttons, .action-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .app-header h1 {
        font-size: 1.8rem;
    }

    .time-display {
        font-size: 2rem;
    }

    .time-input {
        flex-direction: column;
        align-items: center;
        gap: 10px;
    }

    .timer-options {
        flex-direction: column;
        gap: 10px;
    }
}