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

:root {
  --bg: #0b0f1a;
  --panel: #131a2b;
  --panel2: #1a2338;
  --text: #e8ecf6;
  --muted: #8b95ad;
  --accent: #6c5ce7;
  --accent2: #00cec9;
  --danger: #ff6b6b;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: "Segoe UI", system-ui, sans-serif;
  line-height: 1.6;
}

/* ============ NAV ============ */
.nav {
  display: flex; justify-content: space-between; align-items: center;
  padding: 18px 6vw; border-bottom: 1px solid #1e2740;
  position: sticky; top: 0; background: rgba(11,15,26,.85);
  backdrop-filter: blur(10px); z-index: 10;
}
.logo { font-size: 1.3rem; font-weight: 800; }
.logo span { color: var(--accent2); }
.nav a { color: var(--muted); text-decoration: none; margin-left: 24px; }
.nav a:hover { color: var(--text); }
.btn-small { background: var(--accent); color: #fff !important; padding: 8px 18px; border-radius: 8px; }

/* ============ HERO ============ */
.hero { text-align: center; padding: 70px 6vw 30px; }
.hero h1 { font-size: clamp(1.8rem, 4.5vw, 3.2rem); line-height: 1.2; }
.grad {
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero p { max-width: 680px; margin: 18px auto 0; color: var(--muted); }

/* ============ TABS ============ */
.tabs { display: flex; justify-content: center; gap: 12px; margin: 36px 20px 0; flex-wrap: wrap; }
.tab {
  background: var(--panel); color: var(--muted); border: 1px solid #212c4a;
  border-radius: 12px; padding: 14px 28px; font-size: 1rem; font-weight: 600;
  cursor: pointer; transition: .2s;
}
.tab:hover { color: var(--text); }
.tab.active {
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  color: #fff; border-color: transparent;
}

/* ============ TOOL PANELS ============ */
.tool { max-width: 900px; margin: 30px auto 40px; padding: 0 20px; }
.panel {
  background: var(--panel); border: 1px solid #212c4a;
  border-radius: 16px; padding: 30px; margin-bottom: 24px;
}
.hidden { display: none !important; }
.panel-title { margin-bottom: 6px; }
.panel-sub { color: var(--muted); margin-bottom: 18px; }

/* ============ DROPZONE ============ */
.dropzone {
  border: 2px dashed #33406b; border-radius: 14px;
  padding: 60px 20px; text-align: center; cursor: pointer; transition: .25s;
}
.dropzone:hover, .dropzone.dragover {
  border-color: var(--accent2); background: rgba(0,206,201,.05);
}
.drop-icon { font-size: 3rem; margin-bottom: 10px; }
.hint { color: var(--muted); font-size: .85rem; margin-top: 8px; }
.error { color: var(--danger); margin-top: 12px; min-height: 1.2em; }

/* ============ VIDEO + MASK ============ */
.video-wrap {
  position: relative; width: 100%; background: #000;
  border-radius: 12px; overflow: hidden;
}
.video-wrap video { width: 100%; display: block; }
#maskCanvas {
  position: absolute; inset: 0; width: 100%; height: 100%;
  cursor: crosshair; touch-action: none;
}

/* ============ CONTROLS ============ */
.controls { display: flex; flex-wrap: wrap; gap: 18px; align-items: flex-end; margin-top: 20px; }
.controls.center { justify-content: center; }
.control-group { display: flex; flex-direction: column; gap: 6px; }
.control-group label { font-size: .85rem; color: var(--muted); }
input[type=range] { accent-color: var(--accent2); width: 180px; }
input[type=number] {
  background: var(--panel2); border: 1px solid #33406b; color: var(--text);
  border-radius: 8px; padding: 8px 10px; width: 110px;
}

.btn {
  border: none; border-radius: 10px; padding: 12px 26px;
  font-size: 1rem; font-weight: 600; cursor: pointer;
  text-decoration: none; display: inline-block; transition: .2s;
}
.btn.primary { background: linear-gradient(90deg, var(--accent), var(--accent2)); color: #fff; }
.btn.primary:hover { filter: brightness(1.15); transform: translateY(-1px); }
.btn.ghost { background: transparent; color: var(--muted); border: 1px solid #33406b; }
.btn.ghost:hover { color: var(--text); border-color: var(--muted); }

/* ============ PROGRESS ============ */
.progress-track {
  height: 12px; background: var(--panel2); border-radius: 999px;
  overflow: hidden; margin: 20px 0 10px;
}
.progress-bar {
  height: 100%; width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  transition: width .2s;
}

/* ============ QUALITY CARDS ============ */
.quality-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px; margin: 10px 0 4px;
}
.quality-card {
  background: var(--panel2); border: 2px solid #33406b; border-radius: 14px;
  padding: 20px; cursor: pointer; transition: .2s; display: block;
}
.quality-card input { display: none; }
.quality-card:hover { border-color: var(--muted); }
.quality-card:has(input:checked) {
  border-color: var(--accent2); background: rgba(0,206,201,.07);
}
.quality-card h3 { margin-bottom: 6px; font-size: 1.05rem; }
.quality-card p { color: var(--muted); font-size: .88rem; }

/* ============ STEPS ============ */
.steps { max-width: 1000px; margin: 60px auto; padding: 0 20px; text-align: center; }
.steps h2 { font-size: 2rem; margin-bottom: 30px; }
.steps-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; }
.step-card {
  background: var(--panel); border: 1px solid #212c4a;
  border-radius: 14px; padding: 28px; text-align: left;
}
.step-num {
  width: 38px; height: 38px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; margin-bottom: 14px;
}
.step-card p { color: var(--muted); font-size: .95rem; }
.tagline { margin-top: 26px; color: var(--accent2); font-weight: 600; }

footer {
  text-align: center; color: var(--muted); font-size: .85rem;
  padding: 30px; border-top: 1px solid #1e2740; margin-top: 40px;
}

/* ============ ABOUT MODAL ============ */
.modal-overlay {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(0, 0, 0, 0.65);
  display: flex; align-items: center; justify-content: center;
  padding: 20px;
  opacity: 0;
  transition: opacity 250ms ease;
}
.modal-overlay.visible { opacity: 1; }
.modal-overlay[hidden] { display: none; }

.modal {
  background: #ffffff;
  color: #1f2533;
  border-radius: 12px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
  max-width: 650px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  padding: 34px 38px;
  position: relative;
  transform: translateY(10px) scale(0.98);
  transition: transform 250ms ease;
  line-height: 1.65;
}
.modal-overlay.visible .modal { transform: translateY(0) scale(1); }

.modal h2 { font-size: 1.5rem; margin-bottom: 14px; color: #14192b; }
.modal h3 {
  font-size: 1.05rem; margin: 20px 0 8px; color: #14192b;
}
.modal p { margin-bottom: 10px; font-size: .95rem; color: #3a4258; }
.modal strong { color: #14192b; }

.modal-list {
  list-style: none; margin-bottom: 10px;
}
.modal-list li {
  font-size: .95rem; color: #3a4258;
  padding: 3px 0 3px 22px; position: relative;
}
.modal-list li::before {
  content: "•"; position: absolute; left: 6px; color: var(--accent);
  font-weight: 700;
}

.modal-divider {
  border: none; border-top: 1px solid #e6e9f2; margin: 20px 0;
}

.modal-close {
  position: absolute; top: 14px; right: 14px;
  width: 34px; height: 34px; border-radius: 50%;
  border: none; background: #eef0f6; color: #3a4258;
  font-size: .95rem; cursor: pointer; transition: .2s;
  display: flex; align-items: center; justify-content: center;
}
.modal-close:hover { background: #dde1ec; color: #14192b; }
.modal-close:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.github-btn {
  display: inline-flex; align-items: center; gap: 9px;
  background: #14192b; color: #fff; text-decoration: none;
  padding: 12px 22px; border-radius: 10px;
  font-weight: 600; font-size: .95rem;
  margin: 16px 0 6px; transition: .2s;
}
.github-btn:hover { background: #2a3350; transform: translateY(-1px); }
.github-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.github-btn svg { flex-shrink: 0; }

.modal-footer {
  margin-top: 22px; padding-top: 16px;
  border-top: 1px solid #e6e9f2;
  text-align: center; font-size: .85rem; color: #6b7490;
}
.modal-footer strong { color: #3a4258; }

body.modal-open { overflow: hidden; }

@media (max-width: 520px) {
  .modal { padding: 26px 20px; max-height: 90vh; }
  .modal h2 { font-size: 1.3rem; padding-right: 36px; }
}

@media (prefers-reduced-motion: reduce) {
  .modal-overlay, .modal { transition: none; }
}