:root {
    --bg: #060e0a;
    --surface: #0f2018;
    --surface2: #162c20;
    --surface3: #1e3d2a;
    --border: #254535;
    --border2: #2e5840;
    --accent: #00ff9d;
    --accent2: #00d4ff;
    --accent3: #ffb830;
    --text: #f0fff6;
    --text2: #b0e8cc;
    --text3: #7abda0;
    --mono: 'Space Mono', monospace;
    --sans: 'Syne', sans-serif;
    --glow: 0 0 20px rgba(0,255,157,0.15);
    --glow2: 0 0 30px rgba(0,212,255,0.1);
  }

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

  body {
    background: var(--bg);
    color: var(--text);
    font-family: var(--sans);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
  }

  body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image:
      linear-gradient(rgba(0,255,157,0.03) 1px, transparent 1px),
      linear-gradient(90deg, rgba(0,255,157,0.03) 1px, transparent 1px);
    background-size: 40px 40px;
    pointer-events: none;
    z-index: 0;
  }

  body::after {
    content: '';
    position: fixed;
    top: -50%; left: -50%;
    width: 200%; height: 200%;
    background: radial-gradient(ellipse at 70% 20%, rgba(0,255,157,0.04) 0%, transparent 50%),
                radial-gradient(ellipse at 30% 80%, rgba(0,212,255,0.03) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
    animation: drift 20s ease-in-out infinite alternate;
  }

  @keyframes drift {
    from { transform: translate(0,0) rotate(0deg); }
    to   { transform: translate(-20px, 10px) rotate(-1deg); }
  }

  .container {
    position: relative;
    z-index: 1;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px 60px;
  }

  /* ── Security Banner ── */
  .security-banner {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 18px;
    margin-bottom: 24px;
    background: rgba(0,255,157,0.03);
    border: 1px solid rgba(0,255,157,0.12);
    border-radius: 3px;
    font-family: var(--mono);
    font-size: 11px;
    color: #5a9a78;
    letter-spacing: 0.3px;
  }
  .security-banner-icon { font-size: 15px; flex-shrink: 0; opacity: 0.8; }
  .security-banner strong { color: var(--accent); }

  /* ── Paste config banner ── */
  .paste-config-banner {
    display: none;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 10px 18px;
    margin-bottom: 24px;
    background: rgba(0,212,255,0.04);
    border: 1px solid rgba(0,212,255,0.2);
    border-radius: 3px;
    font-family: var(--mono);
    font-size: 11px;
    color: var(--text3);
  }
  .paste-config-banner.visible { display: flex; }
  .paste-config-banner strong { color: var(--accent2); }
  .paste-config-apply-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(0,212,255,0.08);
    border: 1px solid var(--accent2);
    border-radius: 3px;
    font-family: var(--mono);
    font-size: 10px;
    font-weight: 700;
    color: var(--accent2);
    cursor: pointer;
    padding: 5px 12px;
    letter-spacing: 1px;
    white-space: nowrap;
    transition: all 0.2s;
    flex-shrink: 0;
  }
  .paste-config-apply-btn:hover {
    background: rgba(0,212,255,0.16);
    box-shadow: 0 0 12px rgba(0,212,255,0.15);
  }

  .paste-json-btn {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    background: rgba(255,184,48,0.06);
    border: 1px solid rgba(255,184,48,0.35);
    border-radius: 3px;
    font-family: var(--mono);
    font-size: 10px;
    font-weight: 700;
    color: var(--accent3);
    cursor: pointer;
    padding: 6px 14px;
    letter-spacing: 1px;
    transition: all 0.2s;
    white-space: nowrap;
  }

  .paste-json-btn:hover {
    background: rgba(255,184,48,0.14);
    border-color: var(--accent3);
    box-shadow: 0 0 12px rgba(255,184,48,0.15);
  }

  /* ── Header ── */
  header {
    padding: 40px 0 48px;
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    border-bottom: 1px solid var(--border);
    margin-bottom: 40px;
  }

  .logo-group { display: flex; flex-direction: column; gap: 6px; }

  .logo-tag {
    font-family: var(--mono);
    font-size: 11px;
    color: var(--accent);
    letter-spacing: 3px;
    text-transform: uppercase;
  }

  .logo-title {
    font-size: 38px;
    font-weight: 800;
    letter-spacing: -1px;
    color: var(--text);
    line-height: 1;
  }

  .logo-title span { color: var(--accent); }

  .header-right {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 8px;
  }

  .badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 12px;
    border: 1px solid var(--border2);
    border-radius: 2px;
    font-family: var(--mono);
    font-size: 10px;
    color: var(--accent);
    letter-spacing: 1px;
    background: rgba(0,255,157,0.04);
  }

  .badge::before {
    content: '';
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 8px var(--accent);
    animation: pulse 2s ease-in-out infinite;
  }

  @keyframes pulse {
    0%,100% { opacity: 1; }
    50% { opacity: 0.3; }
  }

  .encrypt-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 12px;
    border: 1px dashed var(--border2);
    border-radius: 2px;
    font-family: var(--mono);
    font-size: 10px;
    color: var(--text3);
    letter-spacing: 1px;
    text-decoration: none;
    transition: all 0.2s;
  }

  .encrypt-link:hover {
    border-color: var(--accent2);
    color: var(--accent2);
    background: rgba(0,212,255,0.05);
  }

  /* ── Panels ── */
  .config-panel, .key-section {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 28px;
    margin-bottom: 24px;
    position: relative;
    overflow: hidden;
  }

  .config-panel::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
    opacity: 0.35;
  }

  .key-section::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent3), transparent);
    opacity: 0.3;
  }

  .config-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 24px;
  }

  .config-header-icon {
    width: 28px; height: 28px;
    border: 1px solid var(--border2);
    border-radius: 3px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
    font-size: 14px;
  }

  .config-title {
    font-size: 13px;
    font-weight: 600;
    color: #c0e8d0;
    letter-spacing: 2px;
    text-transform: uppercase;
  }

  .config-grid {
    display: grid;
    grid-template-columns: repeat(3,1fr);
    gap: 16px;
  }

  .field-group { display: flex; flex-direction: column; gap: 8px; }

  .field-label {
    font-family: var(--mono);
    font-size: 10px;
    color: #8abda0;
    letter-spacing: 2px;
    text-transform: uppercase;
  }

  .label-link {
    color: inherit;
    text-decoration: none;
    border-bottom: 1px dashed var(--text3);
    transition: color 0.15s, border-color 0.15s;
  }

  .label-link:hover {
    color: var(--accent);
    border-color: var(--accent);
  }

  .select-wrapper { position: relative; }

  .select-wrapper::after {
    content: '▾';
    position: absolute;
    right: 12px; top: 50%;
    transform: translateY(-50%);
    color: var(--accent);
    font-size: 11px;
    pointer-events: none;
  }

  .field-select, .field-input {
    background: var(--surface2);
    border: 1px solid var(--border);
    color: #dfffee;
    font-family: var(--mono);
    font-size: 13px;
    padding: 10px 14px;
    border-radius: 3px;
    outline: none;
    transition: all 0.2s;
    width: 100%;
    appearance: none;
    -webkit-appearance: none;
    cursor: pointer;
  }

  .field-select:focus, .field-input:focus {
    border-color: var(--accent);
    background: var(--surface3);
    box-shadow: var(--glow);
  }

  /* ── Key / IV Row ── */
  .key-fields {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }

  .key-row {
    display: grid;
    grid-template-columns: 1fr auto auto;
    gap: 8px;
    align-items: flex-end;
  }

  .gen-btn {
    background: var(--surface3);
    border: 1px solid var(--border2);
    color: var(--accent);
    font-family: var(--mono);
    font-size: 11px;
    padding: 10px 16px;
    border-radius: 3px;
    cursor: pointer;
    letter-spacing: 1px;
    transition: all 0.2s;
    white-space: nowrap;
    height: 40px;
  }

  .gen-btn:hover {
    border-color: var(--accent);
    background: rgba(0,255,157,0.08);
    box-shadow: 0 0 15px rgba(0,255,157,0.1);
  }

  .copy-field-btn {
    background: var(--surface3);
    border: 1px solid var(--border2);
    color: #7abda0;
    width: 40px; height: 40px;
    border-radius: 3px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: all 0.2s;
  }

  .copy-field-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(0,255,157,0.08);
  }

  .copy-field-btn.copied {
    border-color: var(--accent2);
    color: var(--accent2);
    background: rgba(0,212,255,0.08);
  }

  .key-hint {
    font-family: var(--mono);
    font-size: 10px;
    color: #6aaa88;
    margin-top: 6px;
  }

  .key-hint span { color: var(--accent); }

  /* ── IO Section ── */
  .io-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 24px;
    align-items: stretch;
  }

  .io-panel {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 4px;
    overflow: hidden;
    position: relative;
    display: flex;
    flex-direction: column;
  }

  .io-panel.input-panel::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; height: 1px;
    background: linear-gradient(90deg, transparent, rgba(0,255,157,0.5), transparent);
  }

  .io-panel.output-panel::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,184,48,0.5), transparent);
  }

  .io-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 18px;
    border-bottom: 1px solid var(--border);
    background: var(--surface2);
  }

  .io-title {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    color: #c0e8d0;
  }

  .io-dot { width: 8px; height: 8px; border-radius: 50%; }
  .input-panel  .io-dot { background: var(--accent);  box-shadow: 0 0 8px var(--accent); }
  .output-panel .io-dot { background: var(--accent3); box-shadow: 0 0 8px var(--accent3); }

  .io-actions { display: flex; gap: 6px; }

  .upload-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 0 12px;
    height: 28px;
    background: rgba(0,255,157,0.08);
    border: 1px solid var(--accent);
    border-radius: 3px;
    color: var(--accent);
    font-family: var(--mono);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1px;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
  }

  .upload-btn:hover {
    background: rgba(0,255,157,0.18);
    box-shadow: 0 0 14px rgba(0,255,157,0.25);
    transform: translateY(-1px);
  }

  .icon-btn {
    background: transparent;
    border: 1px solid var(--border2);
    color: #7abda0;
    width: 28px; height: 28px;
    border-radius: 3px;
    cursor: pointer;
    font-size: 12px;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .icon-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(0,255,157,0.05);
  }

  .io-textarea {
    flex: 1;
    background: transparent;
    border: none;
    color: #e8fff4;
    font-family: var(--mono);
    font-size: 13px;
    line-height: 1.7;
    padding: 18px;
    resize: none;
    outline: none;
    min-height: 180px;
  }

  .io-textarea::placeholder { color: #3a6a50; }

  .io-footer {
    padding: 8px 18px;
    border-top: 1px solid var(--border);
    background: var(--surface2);
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  .io-stat {
    font-family: var(--mono);
    font-size: 10px;
    color: #6aaa88;
  }

  /* Input encoding tabs (for ciphertext) */
  .encoding-tabs { display: flex; gap: 4px; }

  .encoding-tab {
    background: transparent;
    border: 1px solid transparent;
    color: #6aaa88;
    font-family: var(--mono);
    font-size: 10px;
    padding: 3px 8px;
    border-radius: 2px;
    cursor: pointer;
    letter-spacing: 1px;
    transition: all 0.15s;
  }

  .encoding-tab.active {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(0,255,157,0.08);
  }

  /* Drop zone */
  .drop-zone {
    position: absolute;
    inset: 0;
    border: 2px dashed var(--accent);
    border-radius: 4px;
    background: rgba(0,255,157,0.06);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
    z-index: 10;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s;
  }

  .drop-zone.active { opacity: 1; pointer-events: all; }

  .drop-zone-icon { font-size: 28px; color: var(--accent); filter: drop-shadow(0 0 8px var(--accent)); }
  .drop-zone-text { font-family: var(--mono); font-size: 12px; color: var(--accent); letter-spacing: 1px; }

  .file-badge {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 4px 10px;
    background: rgba(0,255,157,0.06);
    border: 1px solid rgba(0,255,157,0.2);
    border-radius: 2px;
    font-family: var(--mono);
    font-size: 10px;
    color: var(--accent);
    max-width: 160px;
    overflow: hidden;
  }

  .file-badge-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

  .file-badge-clear {
    cursor: pointer;
    color: var(--text3);
    flex-shrink: 0;
    transition: color 0.15s;
    background: none;
    border: none;
    font-size: 11px;
    padding: 0;
    line-height: 1;
  }

  .file-badge-clear:hover { color: var(--accent3); }

  /* Output plaintext download strip */
  .output-file-strip {
    display: none;
    align-items: center;
    justify-content: space-between;
    padding: 8px 18px;
    border-top: 1px solid var(--border);
    background: rgba(255,184,48,0.04);
  }

  .output-file-strip.visible { display: flex; }

  .output-file-info {
    font-family: var(--mono);
    font-size: 11px;
    color: var(--accent3);
    display: flex;
    align-items: center;
    gap: 8px;
  }

  .download-file-btn {
    background: rgba(255,184,48,0.08);
    border: 1px solid var(--accent3);
    color: var(--accent3);
    font-family: var(--mono);
    font-size: 10px;
    padding: 5px 12px;
    border-radius: 2px;
    cursor: pointer;
    letter-spacing: 1px;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 6px;
  }

  .download-file-btn:hover {
    background: rgba(255,184,48,0.15);
    box-shadow: 0 0 12px rgba(255,184,48,0.15);
  }

  /* ── Action Row ── */
  .action-row {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 12px;
    margin-bottom: 24px;
    align-items: center;
  }

  .primary-btn {
    padding: 16px 28px;
    border: 1px solid;
    border-radius: 3px;
    font-family: var(--mono);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 2px;
    text-transform: uppercase;
    cursor: pointer;
    transition: all 0.25s;
    position: relative;
    overflow: hidden;
  }

  .decrypt-btn {
    background: rgba(0,255,157,0.08);
    border-color: var(--accent);
    color: var(--accent);
  }

  .decrypt-btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(0,255,157,0.12), transparent);
    opacity: 0;
    transition: opacity 0.25s;
  }

  .decrypt-btn:hover::before { opacity: 1; }

  .decrypt-btn:hover {
    box-shadow: 0 0 30px rgba(0,255,157,0.2), inset 0 0 30px rgba(0,255,157,0.05);
    transform: translateY(-1px);
  }

  .decrypt-btn:active { transform: translateY(0); }

  .encrypt-nav-link {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 0 16px;
    height: 52px;
    background: transparent;
    border: 1px dashed var(--border2);
    border-radius: 3px;
    color: var(--text3);
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 0.5px;
    text-decoration: none;
    white-space: nowrap;
    transition: all 0.2s;
  }

  .encrypt-nav-link:hover {
    border-color: var(--accent2);
    color: var(--accent2);
    background: rgba(0,212,255,0.05);
  }

  /* ── Status Bar ── */
  @keyframes statusShake {
    0%,100% { transform: translateX(0); }
    15%     { transform: translateX(-5px); }
    30%     { transform: translateX(5px); }
    45%     { transform: translateX(-4px); }
    60%     { transform: translateX(4px); }
    75%     { transform: translateX(-2px); }
    90%     { transform: translateX(2px); }
  }
  .status-bar.shake { animation: statusShake 0.45s ease; }

  .status-bar {
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 12px 18px;
    display: flex;
    align-items: center;
    gap: 12px;
    min-height: 46px;
    font-family: var(--mono);
    font-size: 12px;
    margin-bottom: 24px;
    transition: all 0.3s;
  }

  .status-bar.success { border-color: rgba(0,255,157,0.3); background: rgba(0,255,157,0.04); }
  .status-bar.error   { border-color: rgba(255,100,100,0.3); background: rgba(255,100,100,0.04); }

  .status-indicator {
    width: 8px; height: 8px;
    border-radius: 50%;
    background: var(--text3);
    flex-shrink: 0;
    transition: all 0.3s;
  }

  .status-bar.success .status-indicator { background: var(--accent); box-shadow: 0 0 10px var(--accent); }
  .status-bar.error   .status-indicator { background: #ff6464; box-shadow: 0 0 10px #ff6464; }

  .status-text { color: #a0d8b8; flex: 1; }
  .status-bar.success .status-text { color: var(--accent); }
  .status-bar.error   .status-text { color: #ff6464; }
  .status-time { color: #5a9a78; font-size: 10px; }

  /* ── Info Strip ── */
  .info-strip {
    display: grid;
    grid-template-columns: repeat(4,1fr);
    gap: 12px;
  }

  .info-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 16px 18px;
    position: relative;
    overflow: hidden;
  }

  .info-card::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0; height: 2px;
    background: linear-gradient(90deg, var(--accent), transparent);
    opacity: 0.3;
  }

  .info-card-label { font-family: var(--mono); font-size: 9px; color: #5a9a78; letter-spacing: 2px; text-transform: uppercase; margin-bottom: 6px; }
  .info-card-value { font-family: var(--mono); font-size: 18px; font-weight: 700; color: var(--accent); }
  .info-card-sub   { font-size: 11px; color: #6aaa88; margin-top: 3px; }

  /* ── Field validation flash ── */
  @keyframes flashRed {
    0%   { box-shadow: 0 0 0 0 rgba(255,80,80,0); border-color: var(--border); }
    20%  { box-shadow: 0 0 0 3px rgba(255,80,80,0.55); border-color: #ff5050; }
    60%  { box-shadow: 0 0 0 3px rgba(255,80,80,0.25); border-color: #ff5050; }
    100% { box-shadow: 0 0 0 0 rgba(255,80,80,0); border-color: var(--border); }
  }

  .field-error { animation: flashRed 0.75s ease forwards; }

  @keyframes flashRedBorder {
    0%   { border-color: var(--border); box-shadow: 0 0 0 0 rgba(255,80,80,0); }
    20%  { border-color: #ff5050;       box-shadow: 0 0 0 3px rgba(255,80,80,0.4), 0 0 20px rgba(255,80,80,0.2); }
    60%  { border-color: #ff5050;       box-shadow: 0 0 0 2px rgba(255,80,80,0.2); }
    100% { border-color: var(--border); box-shadow: 0 0 0 0 rgba(255,80,80,0); }
  }

  .output-error {
    animation: flashRedBorder 0.9s ease forwards;
  }

  /* ── Toast ── */
  .toast {
    position: fixed;
    bottom: 36px; right: 36px;
    background: var(--surface3);
    border: 1px solid var(--accent);
    border-radius: 4px;
    padding: 14px 22px 14px 16px;
    font-family: var(--mono);
    font-size: 13px;
    font-weight: 700;
    color: var(--accent);
    transform: translateY(20px);
    opacity: 0;
    pointer-events: none;
    transition: all 0.35s cubic-bezier(0.34,1.56,0.64,1);
    z-index: 999;
    box-shadow: 0 8px 32px rgba(0,0,0,0.6), 0 0 24px rgba(0,255,157,0.15);
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 180px;
    letter-spacing: 0.5px;
  }

  .toast::before {
    content: '';
    width: 3px; height: 100%;
    position: absolute;
    left: 0; top: 0;
    background: var(--accent);
    border-radius: 4px 0 0 4px;
    box-shadow: 0 0 10px var(--accent);
  }

  .toast .toast-icon { font-size: 16px; line-height: 1; flex-shrink: 0; }
  .toast.show { transform: translateY(0); opacity: 1; }

  .toast.error-toast {
    border-color: #ff6464;
    color: #ff6464;
    box-shadow: 0 8px 32px rgba(0,0,0,0.6), 0 0 24px rgba(255,100,100,0.15);
  }

  .toast.error-toast::before { background: #ff6464; box-shadow: 0 0 10px #ff6464; }

  /* ── Scan line ── */
  @keyframes scanline {
    0%   { top: -2px; }
    100% { top: 100%; }
  }

  .scan-effect {
    position: fixed;
    left: 0; right: 0; height: 2px;
    background: linear-gradient(transparent, rgba(0,255,157,0.1), transparent);
    pointer-events: none;
    z-index: 200;
    animation: scanline 8s linear infinite;
  }

  @keyframes shimmer {
    from { background-position: -200% 0; }
    to   { background-position: 200% 0; }
  }

  .processing .io-textarea {
    background: linear-gradient(90deg, transparent 25%, rgba(0,255,157,0.04) 50%, transparent 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
  }

  /* ── Explain sections ── */
  .explain-section {
    display: flex;
    gap: 18px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 22px 24px;
    margin-top: 16px;
    scroll-margin-top: 20px;
    position: relative;
    overflow: hidden;
  }

  .explain-section::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; height: 1px;
    background: linear-gradient(90deg, transparent, rgba(0,255,157,0.2), transparent);
  }

  .explain-section:target {
    border-color: var(--accent);
    box-shadow: 0 0 0 1px var(--accent), 0 0 24px rgba(0,255,157,0.1);
  }

  .explain-section:target::before {
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
    opacity: 0.6;
  }

  .explain-icon { font-size: 24px; line-height: 1; flex-shrink: 0; margin-top: 2px; }
  .explain-body { display: flex; flex-direction: column; gap: 10px; }
  .explain-title { font-size: 13px; font-weight: 700; color: #c0e8d0; letter-spacing: 0.3px; }
  .explain-text { font-family: var(--mono); font-size: 12px; line-height: 1.8; color: #6aaa88; }

  @media (max-width: 768px) {
    .config-grid { grid-template-columns: repeat(2,1fr); }
    .io-section { grid-template-columns: 1fr; }
    .action-row { grid-template-columns: 1fr; }
    .info-strip { grid-template-columns: repeat(2,1fr); }
    .key-fields { grid-template-columns: 1fr; }
    .logo-title { font-size: 28px; }
  }