/* ================== DERS PLAYER ================== */
  .lesson-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 18px;
    background: var(--bg-main);
    flex-shrink: 0;
  }

  .close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 20px;
    font-weight: 700;
    cursor: pointer;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .lesson-progress-bar {
    flex: 1;
    height: 10px;
    background: var(--bg-surface);
    border-radius: 6px;
    overflow: hidden;
  }

  .lesson-progress-fill {
    width: 10%;
    height: 100%;
    background: var(--accent-green);
    border-radius: 6px;
    transition: width 0.3s ease;
  }

  .heart-container {
    display: flex;
    gap: 3px;
    font-size: 15px;
  }

  .lesson-step-container {
    flex: 1;
    min-height: 0;
    padding: 16px 18px 20px;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }
  .lesson-step-container::-webkit-scrollbar {
    display: none;
  }

  /* SABİT ALT BUTON BARI (LESSON FOOTER - MOBİL SAFE-AREA UYUMLU) */
  .lesson-footer {
    flex-shrink: 0;
    padding: 12px 18px calc(14px + env(safe-area-inset-bottom, 0px));
    background: var(--bg-surface);
    border-top: 1px solid var(--border-color);
    box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.18);
    z-index: 15;
    display: flex;
    flex-direction: column;
    gap: 6px;
    transition: background 0.25s ease, border-color 0.25s ease;
  }
  [data-theme="light"] .lesson-footer {
    background: #FFFFFF;
    border-top-color: #E2E8F0;
    box-shadow: 0 -4px 16px rgba(15, 23, 42, 0.08);
  }

  .info-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 9px;
    background: rgba(59, 130, 246, 0.15);
    border: 1px solid rgba(59, 130, 246, 0.3);
    border-radius: 6px;
    font-size: 11px;
    font-weight: 700;
    color: #60A5FA;
    width: fit-content;
    margin-bottom: 12px;
  }

  .step-title {
    font-size: 17.5px;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1.35;
    margin-bottom: 12px;
  }

  .info-card-box {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 14px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    box-shadow: var(--shadow-md), inset 0 1px 0 var(--border-highlight);
  }

  .rule-item {
    display: flex;
    align-items: flex-start;
    gap: 10px;
  }

  .rule-icon { font-size: 18px; line-height: 1; }

  .rule-text strong {
    color: #93C5FD;
    display: block;
    font-size: 13.5px;
    margin-bottom: 2px;
  }

  .rule-text p {
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.4;
  }

  .highlight-banner {
    background: rgba(245, 158, 11, 0.1);
    border-left: 3px solid var(--accent-amber);
    padding: 9px 11px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    font-size: 11.5px;
    color: #FCD34D;
    line-height: 1.4;
  }

  .case-box {
    background: var(--case-box-bg);
    border: 1px solid var(--case-box-border);
    border-radius: var(--radius-md);
    padding: 13px 15px;
    margin-bottom: 12px;
    box-shadow: var(--shadow-sm), inset 0 1px 0 var(--border-highlight);
    animation: caseSlideIn 0.22s cubic-bezier(0.16, 1, 0.3, 1);
  }
  @keyframes caseSlideIn {
    0% { opacity: 0; transform: translateY(-8px); }
    100% { opacity: 1; transform: translateY(0); }
  }

  .case-tag {
    font-size: 10.5px;
    font-weight: 800;
    color: var(--accent-blue);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 5px;
  }

  .case-body {
    font-size: 12.5px;
    color: var(--text-primary);
    line-height: 1.45;
  }

  .options-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 14px;
  }

  .options-list .option-btn {
    animation: optSlideUp 0.24s cubic-bezier(0.16, 1, 0.3, 1) backwards;
  }
  .options-list .option-btn:nth-child(1) { animation-delay: 0.04s; }
  .options-list .option-btn:nth-child(2) { animation-delay: 0.08s; }
  .options-list .option-btn:nth-child(3) { animation-delay: 0.12s; }
  .options-list .option-btn:nth-child(4) { animation-delay: 0.16s; }
  .options-list .option-btn:nth-child(5) { animation-delay: 0.20s; }
  @keyframes optSlideUp {
    0% { opacity: 0; transform: translateY(12px); }
    100% { opacity: 1; transform: translateY(0); }
  }

  .option-btn {
    background: var(--bg-surface);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 12px 14px;
    color: var(--text-primary);
    font-size: 12.5px;
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    box-shadow: 0 3px 0 var(--border-color), var(--shadow-sm);
    transition: transform 0.1s ease, box-shadow 0.1s ease, border-color 0.15s ease, background 0.15s ease;
    user-select: none;
  }

  .option-btn:hover {
    border-color: var(--accent-blue);
    transform: translateY(-1px);
    box-shadow: 0 4px 0 var(--border-color), var(--shadow-md);
  }
  .option-btn:active {
    transform: translateY(2px);
    box-shadow: 0 1px 0 var(--border-color);
  }
  .option-btn.selected {
    border-color: var(--accent-blue);
    background: rgba(59, 130, 246, 0.12);
    box-shadow: 0 3px 0 var(--accent-blue), 0 6px 14px rgba(59, 130, 246, 0.25);
  }

  .option-key {
    width: 22px;
    height: 22px;
    border-radius: 6px;
    background: rgba(255, 255, 255, 0.08);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 700;
    color: var(--text-secondary);
    flex-shrink: 0;
  }

  .matching-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    margin-top: 8px;
  }

  .match-col { display: flex; flex-direction: column; gap: 8px; }

  .match-card {
    background: var(--bg-surface);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 10px;
    font-size: 11px;
    font-weight: 600;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    cursor: pointer;
    transition: all 0.15s ease;
    color: var(--text-primary);
    line-height: 1.25;
  }

  .match-card.selected {
    border-color: var(--accent-blue);
    background: rgba(59, 130, 246, 0.2);
  }

  .match-card.matched {
    border-color: var(--accent-green);
    background: rgba(16, 185, 129, 0.15);
    color: #A7F3D0;
    pointer-events: none;
    opacity: 0.6;
  }

  .match-card.wrong {
    border-color: var(--accent-red);
    background: rgba(239, 68, 68, 0.2);
  }

  .bottom-sheet {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--bg-surface);
    border-top: 1px solid var(--border-color);
    padding: 18px 20px calc(18px + env(safe-area-inset-bottom, 0px));
    transform: translateY(110%);
    visibility: hidden;
    pointer-events: none;
    transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), visibility 0s linear 0.25s;
    box-shadow: 0 -10px 30px rgba(0, 0, 0, 0.5);
    z-index: 30;
  }

  .bottom-sheet.open {
    visibility: visible;
    pointer-events: auto;
    transform: translateY(0);
    transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), visibility 0s linear 0s;
  }
  .bottom-sheet.correct { background: #153326; border-color: #24573F; }
  .bottom-sheet.wrong { background: #381A1D; border-color: #5C242A; }

  .feedback-header {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14.5px;
    font-weight: 800;
    margin-bottom: 4px;
  }

  .feedback-header.correct-text { color: #52B788; }
  .feedback-header.wrong-text { color: #E07A7A; }

  .feedback-reason {
    font-size: 12px;
    line-height: 1.4;
    color: #CBD5E1;
    margin-bottom: 12px;
  }

  .primary-btn {
    width: 100%;
    background: var(--accent-blue);
    color: white;
    border: none;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 700;
    cursor: pointer;
    box-shadow: 0 4px 0 var(--accent-blue-dark), 0 4px 8px rgba(0, 0, 0, 0.2);
    transition: transform 0.1s ease, box-shadow 0.1s ease, background 0.15s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    user-select: none;
  }

  .primary-btn:hover { background: var(--accent-blue-hover); }
  .primary-btn:active {
    transform: translateY(3px);
    box-shadow: 0 1px 0 var(--accent-blue-dark), 0 2px 4px rgba(0, 0, 0, 0.15);
  }
  .primary-btn.green {
    background: var(--accent-green);
    box-shadow: 0 4px 0 var(--accent-green-dark), 0 4px 8px rgba(0, 0, 0, 0.2);
  }
  .primary-btn.green:hover { background: var(--accent-green-dark); }
  .primary-btn.green:active {
    transform: translateY(3px);
    box-shadow: 0 1px 0 var(--accent-green-dark), 0 2px 4px rgba(0, 0, 0, 0.15);
  }
  .primary-btn.red {
    background: var(--accent-red);
    box-shadow: 0 4px 0 var(--accent-red-dark), 0 4px 8px rgba(0, 0, 0, 0.2);
  }
  .primary-btn.red:active {
    transform: translateY(3px);
    box-shadow: 0 1px 0 var(--accent-red-dark), 0 2px 4px rgba(0, 0, 0, 0.15);
  }