/* ============================================
   Code.Kitaguru - Mobile Learning Platform CSS
   ============================================ */

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

:root {
    --primary: #6C5CE7;
    --primary-dark: #5A4BD1;
    --secondary: #00CEC9;
    --bg: #0F0F1A;
    --bg-card: #1A1A2E;
    --bg-editor: #1E1E2E;
    --text: #EAEAEA;
    --text-dim: #8888AA;
    --success: #00B894;
    --danger: #FF6B6B;
    --border: #2D2D44;
    --radius: 12px;
    --radius-sm: 8px;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    overflow-x: hidden;
}

/* ============ PAGE SYSTEM ============ */
.page { display: none; padding: 16px; max-width: 480px; margin: 0 auto; }
.page.active { display: block; }

/* ============ LANDING ============ */
.hero { text-align: center; padding: 48px 16px 24px; }
.logo-text { font-size: 28px; font-weight: 800; color: var(--primary); margin-bottom: 8px; }
.logo-text span { color: var(--text); }
.subtitle { font-size: 18px; font-weight: 600; color: var(--text); margin-bottom: 8px; }
.desc { font-size: 14px; color: var(--text-dim); line-height: 1.6; margin-bottom: 24px; }

.btn-primary {
    background: var(--primary);
    color: #fff;
    border: none;
    padding: 14px 36px;
    border-radius: var(--radius);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    width: 100%;
    max-width: 280px;
}
.btn-primary:active { transform: scale(0.97); background: var(--primary-dark); }
.btn-secondary {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
    padding: 12px 28px;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}
.btn-secondary:active { background: var(--primary); color: #fff; }
.btn-sm {
    background: var(--secondary);
    color: #000;
    border: none;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
}
.btn-xs {
    background: transparent;
    color: var(--text-dim);
    border: 1px solid var(--border);
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    font-size: 12px;
    cursor: pointer;
}
.btn-back {
    background: transparent;
    color: var(--text);
    border: none;
    font-size: 20px;
    cursor: pointer;
    padding: 4px 8px;
}

.features { display: grid; gap: 12px; padding: 24px 0; }
.feature {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--bg-card);
    padding: 14px 16px;
    border-radius: var(--radius-sm);
    font-size: 14px;
}
.feature .icon { font-size: 20px; }

/* ============ MODE SELECTION ============ */
.page-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 0;
    margin-bottom: 16px;
}
.page-header h2 { font-size: 18px; flex: 1; }
.badge {
    background: var(--primary);
    color: #fff;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.mode-cards { display: grid; gap: 16px; padding-top: 24px; }
.mode-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    cursor: pointer;
    transition: all 0.2s;
}
.mode-card:active { transform: scale(0.98); border-color: var(--primary); }
.mode-card .icon { font-size: 32px; display: block; margin-bottom: 12px; }
.mode-card h3 { font-size: 18px; margin-bottom: 8px; }
.mode-card p { font-size: 13px; color: var(--text-dim); line-height: 1.5; }

/* ============ LESSON LIST ============ */
.lesson-list { display: grid; gap: 12px; }
.lesson-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 16px;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.lesson-card:active { transform: scale(0.98); border-color: var(--primary); }
.lesson-card.completed { border-left: 3px solid var(--success); }
.lesson-card .lesson-info h4 { font-size: 14px; margin-bottom: 4px; }
.lesson-card .lesson-info p { font-size: 12px; color: var(--text-dim); }
.lesson-card .lesson-status { font-size: 12px; color: var(--text-dim); }
.lesson-card .lesson-status.done { color: var(--success); }

/* ============ EDITOR ============ */
.editor-container { margin-bottom: 8px; }
.editor-tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 4px;
}
.editor-tabs .tab {
    background: var(--bg-card);
    color: var(--text-dim);
    border: 1px solid var(--border);
    padding: 8px 16px;
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
    font-size: 13px;
    cursor: pointer;
    font-weight: 500;
}
.editor-tabs .tab.active {
    background: var(--bg-editor);
    color: var(--text);
    border-bottom-color: var(--bg-editor);
}
.code-editor {
    width: 100%;
    height: 200px;
    background: var(--bg-editor);
    color: #E0E0E0;
    border: 1px solid var(--border);
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    padding: 12px;
    font-family: 'Courier New', monospace;
    font-size: 13px;
    line-height: 1.6;
    resize: vertical;
    outline: none;
    tab-size: 2;
}
.code-editor:focus { border-color: var(--primary); }

.preview-container {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    overflow: hidden;
    margin-top: 8px;
}
.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 12px;
    font-size: 13px;
    color: var(--text-dim);
    border-bottom: 1px solid var(--border);
}
.preview-frame {
    width: 100%;
    height: 300px;
    border: none;
    background: #fff;
}

/* ============ RESULT ============ */
.result-container { margin-bottom: 16px; }
.result-frame {
    width: 100%;
    height: 400px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: #fff;
}
.result-actions { display: flex; gap: 12px; }
.result-actions button { flex: 1; }

/* ============ RESPONSIVE ============ */
@media (min-width: 768px) {
    .page { max-width: 600px; }
    .code-editor { height: 250px; }
    .preview-frame { height: 400px; }
}