@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

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

:root {
    --primary-color: #1a73e8;
    --success-color: #34a853;
    --text-primary: #202124;
    --text-secondary: #5f6368;
    --border-color: #dadce0;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --hover-bg: #f1f3f4;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: var(--bg-primary);
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
    overflow: hidden;
}

/* Header */
.header {
    padding: 32px 32px 24px;
    border-bottom: 1px solid var(--border-color);
}

.header h1 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.subtitle {
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 400;
}

/* Progress Summary */
.progress-summary {
    display: flex;
    gap: 32px;
    padding: 20px 32px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
}

.progress-item {
    display: flex;
    align-items: baseline;
    gap: 8px;
}

.progress-label {
    font-size: 13px;
    color: var(--text-secondary);
}

.progress-value {
    font-size: 20px;
    font-weight: 600;
    color: var(--primary-color);
}

.progress-total {
    font-size: 14px;
    color: var(--text-secondary);
}

/* Modules Container */
.modules-container {
    padding: 24px 32px 32px;
}

.module-card {
    padding: 20px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 16px;
    transition: all 0.2s ease;
    background: var(--bg-primary);
}

.module-card:hover {
    border-color: var(--primary-color);
    box-shadow: 0 1px 3px rgba(26, 115, 232, 0.12);
}

.module-card.module-final {
    border-color: #fbbc04;
    background: #fffbf2;
}

.module-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.module-header h2 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
}

.module-progress {
    font-size: 13px;
    color: var(--success-color);
    font-weight: 500;
    padding: 4px 12px;
    background: #e6f4ea;
    border-radius: 12px;
}

.module-status {
    font-size: 12px;
    color: var(--text-secondary);
    padding: 4px 12px;
    background: var(--bg-secondary);
    border-radius: 12px;
}

.module-desc {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 16px;
    line-height: 1.5;
}

/* Buttons */
.btn-module {
    background: var(--bg-primary);
    color: var(--primary-color);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: 4px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-module:hover {
    background: var(--hover-bg);
    border-color: var(--primary-color);
}

.btn-module.btn-disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-module.btn-disabled:hover {
    background: var(--bg-primary);
    border-color: var(--border-color);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    overflow-y: auto;
}

.modal-content {
    background: var(--bg-primary);
    margin: 40px auto;
    padding: 0;
    border-radius: 8px;
    max-width: 800px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.24);
    position: relative;
}

.modal-close {
    position: absolute;
    right: 16px;
    top: 16px;
    background: transparent;
    border: none;
    font-size: 24px;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 4px;
    transition: all 0.2s ease;
    z-index: 10;
}

.modal-close:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

/* Level Header */
.level-header {
    padding: 24px 32px;
    border-bottom: 1px solid var(--border-color);
}

.level-header h2 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.level-header p {
    font-size: 14px;
    color: var(--text-secondary);
}

/* Level Navigation */
.level-nav {
    display: flex;
    gap: 8px;
    padding: 16px 32px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    overflow-x: auto;
}

.level-nav-btn {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: 16px;
    font-size: 13px;
    color: var(--text-primary);
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.2s ease;
    font-weight: 500;
}

.level-nav-btn:hover {
    border-color: var(--primary-color);
    background: var(--hover-bg);
}

.level-nav-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.level-nav-btn.completed {
    background: #e6f4ea;
    border-color: var(--success-color);
    color: var(--success-color);
}

/* Level Content */
.level-content {
    padding: 32px;
    max-height: calc(100vh - 300px);
    overflow-y: auto;
}

.level-content h2 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 20px;
}

.level-content h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 24px 0 12px 0;
}

.level-content h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 16px 0 8px 0;
}

.level-content p {
    font-size: 14px;
    color: var(--text-primary);
    line-height: 1.6;
    margin-bottom: 12px;
}

.level-content ul,
.level-content ol {
    margin: 12px 0;
    padding-left: 24px;
}

.level-content li {
    font-size: 14px;
    color: var(--text-primary);
    margin-bottom: 8px;
    line-height: 1.6;
}

.level-content strong {
    font-weight: 600;
    color: var(--text-primary);
}

.level-content code {
    background: var(--bg-secondary);
    padding: 2px 6px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    font-size: 13px;
    color: #c7254e;
}

/* Tip Box */
.tip-box {
    background: #e8f0fe;
    border-left: 4px solid var(--primary-color);
    padding: 16px;
    margin: 20px 0;
    border-radius: 4px;
}

.tip-box strong {
    color: var(--primary-color);
    display: block;
    margin-bottom: 8px;
}

/* Task List */
.task-list {
    margin: 20px 0;
}

.task-item {
    display: flex;
    align-items: flex-start;
    padding: 12px;
    margin-bottom: 8px;
    border-radius: 4px;
    transition: background 0.2s ease;
}

.task-item:hover {
    background: var(--hover-bg);
}

.task-checkbox {
    margin-right: 12px;
    margin-top: 2px;
    cursor: pointer;
    width: 18px;
    height: 18px;
}

.task-label {
    font-size: 14px;
    color: var(--text-primary);
    cursor: pointer;
    flex: 1;
    line-height: 1.5;
}

.task-item.completed .task-label {
    text-decoration: line-through;
    color: var(--text-secondary);
}

/* Complete Button */
.complete-level-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 4px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    margin-top: 24px;
    transition: all 0.2s ease;
}

.complete-level-btn:hover {
    background: #1765cc;
}

.complete-level-btn:disabled {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: not-allowed;
}

/* Scrollbar */
.modal-content::-webkit-scrollbar,
.level-content::-webkit-scrollbar {
    width: 8px;
}

.modal-content::-webkit-scrollbar-track,
.level-content::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

.modal-content::-webkit-scrollbar-thumb,
.level-content::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

.modal-content::-webkit-scrollbar-thumb:hover,
.level-content::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* Responsive */
@media (max-width: 768px) {
    body {
        padding: 0;
    }

    .container {
        border-radius: 0;
    }

    .header {
        padding: 24px 20px 20px;
    }

    .header h1 {
        font-size: 20px;
    }

    .progress-summary {
        padding: 16px 20px;
        gap: 24px;
    }

    .modules-container {
        padding: 20px;
    }

    .module-card {
        padding: 16px;
    }

    .modal-content {
        margin: 20px;
        max-width: calc(100% - 40px);
    }

    .level-content {
        padding: 24px 20px;
    }

    .level-nav {
        padding: 12px 20px;
    }
}