:root {
    --ielts-primary: #0057B8;
    --ielts-accent: #E4002B;
    --ielts-bg: #ffffff;
    --ielts-passage-bg: #f8f9fa;
    --ielts-text: #333333;
    --ielts-border: #d0d0d0;
    --ielts-font: 'Segoe UI', Arial, sans-serif;
    --ielts-base-size: 16px;
}

/* Landing */
.ielts-landing { max-width: 1100px; margin: 0 auto; padding: 20px; }
.ielts-landing-header { text-align: center; margin-bottom: 40px; }
.ielts-landing-header h2 { font-size: 32px; color: var(--ielts-primary); margin-bottom: 10px; }
.ielts-landing-header p { color: #666; font-size: 16px; }
.ielts-books-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 20px; }
.ielts-book-card { background: #fff; border: 1px solid var(--ielts-border); border-radius: 8px; overflow: hidden; box-shadow: 0 2px 8px rgba(0,0,0,0.06); }
.ielts-book-card .book-header { background: var(--ielts-primary); color: #fff; padding: 15px 20px; display: flex; justify-content: space-between; align-items: center; }
.ielts-book-card .book-header h3 { margin: 0; font-size: 18px; }
.ielts-book-card .book-year { background: rgba(255,255,255,0.2); padding: 3px 10px; border-radius: 12px; font-size: 13px; }
.ielts-tests-list { padding: 15px; }
.ielts-test-row { display: flex; justify-content: space-between; align-items: center; padding: 12px 0; border-bottom: 1px solid #eee; }
.ielts-test-row:last-child { border-bottom: none; }
.ielts-test-row .test-name { font-weight: 600; color: #333; }
.ielts-test-row .test-sections { display: flex; gap: 8px; }
.ielts-section-link { display: inline-block; padding: 6px 14px; border-radius: 4px; text-decoration: none; font-size: 13px; font-weight: 500; transition: all 0.2s; }
.ielts-section-link.listening { background: #e3f2fd; color: var(--ielts-primary); border: 1px solid #bbdefb; }
.ielts-section-link.listening:hover { background: var(--ielts-primary); color: #fff; }
.ielts-section-link.reading { background: #e8f5e9; color: #2e7d32; border: 1px solid #c8e6c9; }
.ielts-section-link.reading:hover { background: #2e7d32; color: #fff; }
.ielts-section-link .time { opacity: 0.7; font-size: 11px; margin-left: 3px; }

/* Test Wrapper */
.ielts-test-wrapper { position: fixed; top: 0; left: 0; right: 0; bottom: 0; z-index: 9999; background: var(--ielts-bg); font-family: var(--ielts-font); font-size: var(--ielts-base-size); }
.ielts-top-bar { position: absolute; top: 0; left: 0; right: 0; height: 50px; background: var(--ielts-primary); color: #fff; display: flex; align-items: center; justify-content: space-between; padding: 0 20px; z-index: 10; }
.ielts-test-info { display: flex; gap: 15px; align-items: center; font-size: 14px; }
.ielts-test-info .book-name { font-weight: 600; }
.ielts-test-info .section-type { background: rgba(255,255,255,0.2); padding: 2px 10px; border-radius: 12px; font-size: 12px; text-transform: uppercase; }
.ielts-timer { font-size: 24px; font-weight: bold; font-family: 'Courier New', monospace; letter-spacing: 2px; }
.ielts-timer.warning { color: #ffeb3b; animation: timer-blink 1s infinite; }
.ielts-timer.danger { color: #ff5252; animation: timer-blink 0.5s infinite; }
@keyframes timer-blink { 0%, 100% { opacity: 1; } 50% { opacity: 0.5; } }
.ielts-top-actions { display: flex; gap: 10px; }
.ielts-btn-settings, .ielts-btn-hide { background: rgba(255,255,255,0.15); border: 1px solid rgba(255,255,255,0.3); color: #fff; padding: 6px 14px; border-radius: 4px; cursor: pointer; font-size: 13px; transition: all 0.2s; }
.ielts-btn-settings:hover, .ielts-btn-hide:hover { background: rgba(255,255,255,0.3); }

/* Main Container */
.ielts-test-container { position: absolute; top: 50px; bottom: 70px; left: 0; right: 0; display: flex; overflow: hidden; }
.ielts-passage-panel { width: 50%; border-right: 2px solid var(--ielts-border); overflow-y: auto; padding: 20px; background: var(--ielts-passage-bg); position: relative; }
.ielts-passage-tools { position: sticky; top: 0; background: var(--ielts-passage-bg); padding: 10px 0; margin-bottom: 10px; border-bottom: 1px solid #e0e0e0; z-index: 5; }
.ielts-tool-btn { background: #fff; border: 1px solid var(--ielts-border); padding: 5px 12px; margin-right: 5px; border-radius: 4px; cursor: pointer; font-size: 13px; }
.ielts-tool-btn:hover, .ielts-tool-btn.active { background: var(--ielts-primary); color: #fff; border-color: var(--ielts-primary); }
.ielts-paragraph { line-height: 1.9; color: var(--ielts-text); font-size: var(--ielts-base-size); }
.ielts-paragraph p { margin-bottom: 12px; }
.ielts-highlight { background-color: #ffeb3b !important; padding: 2px 0; }
.ielts-underline { text-decoration: underline; text-decoration-color: var(--ielts-primary); text-decoration-thickness: 2px; }

/* Listening Panel */
.ielts-listening-panel .ielts-audio-wrapper { position: sticky; top: 0; background: var(--ielts-passage-bg); padding: 15px; margin: -20px -20px 15px -20px; border-bottom: 2px solid var(--ielts-border); z-index: 5; }
.ielts-listening-panel audio { width: 100%; height: 40px; }
.ielts-volume-wrap { display: flex; align-items: center; gap: 10px; margin-top: 8px; }
.ielts-volume-wrap label { font-size: 13px; color: #666; }
.ielts-volume-wrap input[type="range"] { flex: 1; }
.ielts-paragraph-wrapper { margin-top: 10px; }
.ielts-paragraph .sync-line { display: block; padding: 3px 6px; margin: 2px 0; border-radius: 3px; transition: background 0.3s ease; }
.ielts-paragraph .sync-line.active { background: #fff59d; font-weight: 500; }

/* Questions Panel */
.ielts-questions-panel { width: 50%; overflow-y: auto; padding: 20px; background: var(--ielts-bg); }
.ielts-questions-list { padding-bottom: 30px; }
.ielts-question-item { margin-bottom: 25px; padding: 18px; border: 1px solid var(--ielts-border); border-radius: 6px; background: #fff; transition: box-shadow 0.2s; }
.ielts-question-item:hover { box-shadow: 0 2px 8px rgba(0,0,0,0.06); }
.ielts-question-item.current { border-color: var(--ielts-primary); box-shadow: 0 0 0 2px rgba(0,87,184,0.15); }
.ielts-question-header { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-bottom: 10px; padding-bottom: 8px; border-bottom: 1px solid #f0f0f0; }
.ielts-question-number { font-weight: bold; color: var(--ielts-primary); font-size: 15px; }
.ielts-question-instruction { font-size: 13px; color: #666; font-style: italic; }
.ielts-word-limit { font-size: 12px; color: var(--ielts-accent); font-weight: 600; }
.ielts-question-text { margin-bottom: 12px; line-height: 1.7; }
.ielts-answer-area { margin-top: 10px; }
.ielts-answer-input { width: 100%; max-width: 400px; padding: 10px 14px; border: 1px solid #999; border-radius: 4px; font-size: var(--ielts-base-size); transition: all 0.2s; }
.ielts-answer-input:focus { border-color: var(--ielts-primary); outline: none; box-shadow: 0 0 0 3px rgba(0,87,184,0.15); }
.ielts-answer-select { width: 100%; max-width: 400px; padding: 10px 14px; border: 1px solid #999; border-radius: 4px; font-size: var(--ielts-base-size); background: #fff; }
.ielts-option { display: block; padding: 10px 12px; margin: 6px 0; border: 1px solid var(--ielts-border); border-radius: 4px; cursor: pointer; transition: all 0.2s; background: #fafafa; }
.ielts-option:hover { background: #e3f2fd; border-color: var(--ielts-primary); }
.ielts-option input { margin-right: 10px; }
.ielts-option.selected { background: #e3f2fd; border-color: var(--ielts-primary); }
.ielts-submit-area { margin-top: 30px; padding-top: 20px; border-top: 2px solid var(--ielts-border); text-align: center; }
.ielts-btn-submit { background: var(--ielts-primary); color: #fff; border: none; padding: 14px 50px; font-size: 16px; font-weight: 600; border-radius: 6px; cursor: pointer; transition: all 0.2s; }
.ielts-btn-submit:hover { background: #004494; transform: translateY(-1px); box-shadow: 0 4px 12px rgba(0,87,184,0.3); }

/* Bottom Nav */
.ielts-bottom-nav { position: absolute; bottom: 0; left: 0; right: 0; height: 70px; background: #f0f0f0; border-top: 2px solid var(--ielts-border); display: flex; align-items: center; padding: 0 15px; gap: 15px; }
.ielts-nav-info { min-width: 80px; }
.ielts-btn-review { background: #fff; border: 2px solid var(--ielts-accent); color: var(--ielts-accent); padding: 8px 16px; border-radius: 4px; font-weight: 600; cursor: pointer; font-size: 13px; }
.ielts-btn-review.active { background: var(--ielts-accent); color: #fff; }
.ielts-question-nav { display: flex; gap: 3px; flex-wrap: wrap; flex: 1; justify-content: center; max-height: 50px; overflow-y: auto; }
.ielts-q-btn { width: 32px; height: 32px; border: 1px solid #bbb; background: #fff; font-size: 12px; cursor: pointer; display: flex; align-items: center; justify-content: center; border-radius: 3px; transition: all 0.2s; }
.ielts-q-btn:hover { background: #e3f2fd; border-color: var(--ielts-primary); }
.ielts-q-btn.active { background: var(--ielts-primary); color: #fff; border-color: var(--ielts-primary); }
.ielts-q-btn.answered { background: #c8e6c9; border-color: #4caf50; color: #2e7d32; font-weight: bold; }
.ielts-q-btn.review { border-radius: 50%; border-color: var(--ielts-accent); border-width: 2px; }
.ielts-nav-arrows { display: flex; gap: 5px; }
.ielts-btn-prev, .ielts-btn-next { width: 36px; height: 36px; border: 1px solid #bbb; background: #fff; cursor: pointer; border-radius: 4px; font-size: 16px; }
.ielts-btn-prev:hover, .ielts-btn-next:hover { background: var(--ielts-primary); color: #fff; border-color: var(--ielts-primary); }

/* Settings Modal */
.ielts-settings-modal { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); z-index: 10000; align-items: center; justify-content: center; }
.ielts-settings-modal.open { display: flex; }
.ielts-settings-modal .ielts-modal-content { background: #fff; padding: 30px; border-radius: 8px; width: 400px; max-width: 90%; box-shadow: 0 10px 40px rgba(0,0,0,0.2); }
.ielts-settings-modal h3 { margin-top: 0; color: var(--ielts-primary); border-bottom: 2px solid var(--ielts-primary); padding-bottom: 10px; margin-bottom: 20px; }
.ielts-setting-group { margin-bottom: 20px; }
.ielts-setting-group label { display: block; font-weight: 600; margin-bottom: 10px; color: #333; }
.ielts-font-options, .ielts-bg-options { display: flex; gap: 8px; }
.ielts-font-btn, .ielts-bg-btn { flex: 1; padding: 10px; border: 2px solid #ddd; background: #fff; cursor: pointer; border-radius: 4px; font-size: 13px; transition: all 0.2s; }
.ielts-font-btn.active, .ielts-bg-btn.active { border-color: var(--ielts-primary); background: #e3f2fd; color: var(--ielts-primary); font-weight: 600; }
.ielts-btn-close-modal { width: 100%; padding: 12px; background: var(--ielts-primary); color: #fff; border: none; border-radius: 4px; font-size: 15px; font-weight: 600; cursor: pointer; margin-top: 10px; }

/* Pause Overlay */
.ielts-pause-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.85); z-index: 10001; align-items: center; justify-content: center; }
.ielts-pause-overlay.open { display: flex; }
.pause-content { text-align: center; color: #fff; }
.pause-content h2 { font-size: 36px; margin-bottom: 15px; }
.pause-content p { font-size: 18px; margin-bottom: 30px; opacity: 0.8; }
.ielts-btn-resume { padding: 14px 50px; font-size: 18px; background: var(--ielts-primary); color: #fff; border: none; border-radius: 6px; cursor: pointer; }

/* Results */
.ielts-results-page { max-width: 900px; margin: 40px auto; padding: 20px; }
.ielts-results-header { text-align: center; padding: 40px; background: #fff; border-radius: 12px; box-shadow: 0 2px 12px rgba(0,0,0,0.08); margin-bottom: 30px; }
.ielts-results-header h2 { color: var(--ielts-primary); margin-bottom: 20px; }
.ielts-score-circle { display: inline-flex; flex-direction: column; align-items: center; justify-content: center; width: 140px; height: 140px; border-radius: 50%; background: var(--ielts-primary); color: #fff; margin: 20px auto; }
.ielts-score-circle .score-number { font-size: 48px; font-weight: bold; line-height: 1; }
.ielts-score-circle .score-total { font-size: 20px; opacity: 0.8; }
.ielts-band-score { font-size: 28px; font-weight: bold; color: var(--ielts-accent); margin: 10px 0; }
.ielts-percentage { font-size: 18px; color: #666; }
.ielts-answers-review { background: #fff; border-radius: 12px; padding: 30px; box-shadow: 0 2px 12px rgba(0,0,0,0.08); margin-bottom: 30px; }
.ielts-answers-review h3 { color: var(--ielts-primary); margin-bottom: 20px; padding-bottom: 10px; border-bottom: 2px solid #eee; }
.ielts-review-item { padding: 15px; margin-bottom: 15px; border-radius: 6px; border-left: 4px solid; }
.ielts-review-item.correct { background: #e8f5e9; border-left-color: #4caf50; }
.ielts-review-item.incorrect { background: #ffebee; border-left-color: #f44336; }
.review-question { margin-bottom: 8px; font-weight: 500; }
.review-question .q-num { color: var(--ielts-primary); margin-right: 5px; }
.review-answers { display: flex; gap: 20px; font-size: 14px; }
.user-answer { color: #666; }
.correct-answer { color: #2e7d32; font-weight: 600; }
.ielts-results-actions { display: flex; justify-content: center; gap: 15px; flex-wrap: wrap; }
.ielts-btn-next-test, .ielts-btn-back { display: inline-block; padding: 14px 35px; border-radius: 6px; text-decoration: none; font-weight: 600; font-size: 15px; transition: all 0.2s; }
.ielts-btn-next-test { background: var(--ielts-primary); color: #fff; }
.ielts-btn-next-test:hover { background: #004494; }
.ielts-btn-back { background: #f0f0f0; color: #333; border: 1px solid #ddd; }
.ielts-btn-back:hover { background: #e0e0e0; }

/* Themes */
.ielts-test-wrapper.theme-dark { --ielts-bg: #1a1a1a; --ielts-passage-bg: #2d2d2d; --ielts-text: #e0e0e0; --ielts-border: #444; }
.ielts-test-wrapper.theme-dark .ielts-question-item, .ielts-test-wrapper.theme-dark .ielts-option { background: #2d2d2d; border-color: #444; color: #e0e0e0; }
.ielts-test-wrapper.theme-dark .ielts-answer-input, .ielts-test-wrapper.theme-dark .ielts-answer-select { background: #333; color: #e0e0e0; border-color: #555; }
.ielts-test-wrapper.theme-blue { --ielts-passage-bg: #e8eaf6; }

/* Responsive */
@media (max-width: 900px) {
    .ielts-test-container { flex-direction: column; }
    .ielts-passage-panel, .ielts-questions-panel { width: 100%; height: 50%; }
    .ielts-passage-panel { border-right: none; border-bottom: 2px solid var(--ielts-border); }
}