:root {
  --bg: #f4f6f8;
  --bg-soft: #eef2f5;
  --surface: #ffffff;
  --ink: #1a2330;
  --muted: #5b6b7c;
  --line: #dbe3ea;
  --accent: #1f6f78;
  --accent-soft: #e6f3f4;
  --accent-strong: #17565d;
  --warn: #8a4b2f;
  --warn-soft: #f7eee8;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 1px 2px rgba(26, 35, 48, 0.04), 0 12px 32px rgba(26, 35, 48, 0.06);
  --font-display: "Fraunces", Georgia, serif;
  --font-body: "Source Sans 3", "Segoe UI", sans-serif;
  --max: 980px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  color: var(--ink);
  background:
    linear-gradient(180deg, #f7f9fb 0%, var(--bg) 38%, #f2f5f7 100%);
  line-height: 1.6;
  font-size: 1.02rem;
  -webkit-tap-highlight-color: transparent;
}

.workspace,
.brand,
.dropzone,
.mode-tabs {
  -webkit-user-select: none;
  user-select: none;
}

.faq-body,
.section-lead,
.hero-lead,
.tutorial-item p,
input,
textarea,
select {
  -webkit-user-select: text;
  user-select: text;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input,
select {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(247, 249, 251, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease;
}

.site-header.is-scrolled {
  border-bottom-color: var(--line);
}

.nav {
  width: min(100% - 2rem, var(--max));
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.95rem 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.02em;
  font-size: 1.12rem;
}

.brand-mark {
  width: 2.1rem;
  height: 2.1rem;
  border-radius: 0.65rem;
  display: grid;
  place-items: center;
  color: #fff;
  background: var(--accent);
}

.brand-mark svg {
  width: 1.05rem;
  height: 1.05rem;
}

.nav-links {
  display: flex;
  gap: 1.15rem;
  color: var(--muted);
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: var(--accent);
}

.hero {
  width: min(100% - 2rem, var(--max));
  margin: 0 auto;
  padding: 2.75rem 0 1.5rem;
}

.hero-copy {
  max-width: 36rem;
  margin-bottom: 1.75rem;
}

.hero-kicker {
  margin: 0 0 0.7rem;
  color: var(--accent);
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.brand-hero {
  font-family: var(--font-display);
  font-size: clamp(2.35rem, 5.5vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  font-weight: 600;
  margin: 0 0 0.85rem;
  color: var(--ink);
}

.brand-hero span {
  color: var(--accent);
}

.hero-lead {
  margin: 0 0 1.25rem;
  color: var(--muted);
  font-size: 1.08rem;
  max-width: 32rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.btn {
  appearance: none;
  border: 0;
  cursor: pointer;
  border-radius: 999px;
  padding: 0.78rem 1.2rem;
  font-weight: 600;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn-primary {
  color: #fff;
  background: var(--accent);
}

.btn-primary:hover {
  background: var(--accent-strong);
}

.btn-ghost {
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line);
}

.btn-ghost:hover {
  border-color: #c8d3dd;
}

.btn-small {
  padding: 0.5rem 0.9rem;
  font-size: 0.92rem;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.workspace {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  box-shadow: var(--shadow);
  padding: 1.15rem;
}

.mode-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.35rem;
  margin-bottom: 0.85rem;
  padding: 0.3rem;
  border-radius: 12px;
  background: var(--bg-soft);
}

.mode-tab {
  border: 0;
  background: transparent;
  border-radius: 9px;
  padding: 0.7rem 0.5rem;
  cursor: pointer;
  color: var(--muted);
  font-weight: 600;
  transition: background 0.2s ease, color 0.2s ease;
}

.mode-tab.is-active {
  background: var(--surface);
  color: var(--ink);
  box-shadow: 0 1px 2px rgba(26, 35, 48, 0.06);
}

.mode-desc {
  margin: 0 0 1rem;
  color: var(--muted);
  font-size: 0.96rem;
}

.dropzone {
  border: 1px dashed #b9c7d3;
  border-radius: var(--radius);
  background: #fafcfd;
  min-height: 190px;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 1.75rem 1.1rem;
  cursor: pointer;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.dropzone.is-dragover {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.dropzone-inner {
  display: grid;
  gap: 0.4rem;
  justify-items: center;
}

.drop-icon {
  width: 2.8rem;
  height: 2.8rem;
  border-radius: 0.85rem;
  display: grid;
  place-items: center;
  background: var(--accent-soft);
  color: var(--accent);
  margin-bottom: 0.25rem;
}

.dropzone h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.dropzone p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.file-input {
  display: none;
}

.controls {
  display: grid;
  gap: 1rem;
  margin-top: 1rem;
  padding: 1rem;
  border-radius: var(--radius);
  background: var(--bg);
  border: 1px solid var(--line);
}

.controls-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.85rem;
}

.field {
  display: grid;
  gap: 0.35rem;
}

.field label {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--muted);
}

.field select,
.field input[type="number"] {
  width: 100%;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.75rem;
  color: var(--ink);
  outline: none;
}

.field select:focus,
.field input[type="number"]:focus {
  border-color: #9ec4c8;
  box-shadow: 0 0 0 3px rgba(31, 111, 120, 0.12);
}

.quality-row {
  display: grid;
  gap: 0.4rem;
}

.quality-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.9rem;
  color: var(--muted);
}

.quality-head strong {
  color: var(--accent);
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.controls-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  justify-content: space-between;
}

.hint {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0;
}

.queue {
  margin-top: 1rem;
  display: grid;
  gap: 0.65rem;
}

.queue-item,
.result-card {
  display: grid;
  grid-template-columns: 56px 1fr auto;
  gap: 0.85rem;
  align-items: center;
  padding: 0.7rem;
  border-radius: 12px;
  background: var(--surface);
  border: 1px solid var(--line);
}

.queue-thumb,
.result-preview {
  width: 56px;
  height: 56px;
  border-radius: 10px;
  object-fit: cover;
  background: var(--bg-soft);
}

.result-preview {
  width: 64px;
  height: 64px;
}

.queue-meta strong,
.result-info h3 {
  display: block;
  margin: 0 0 0.15rem;
  font-size: 0.96rem;
  font-weight: 600;
}

.queue-meta span,
.result-info p {
  margin: 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.queue-remove {
  border: 0;
  background: var(--warn-soft);
  color: var(--warn);
  width: 1.9rem;
  height: 1.9rem;
  border-radius: 999px;
  cursor: pointer;
  font-size: 1.05rem;
  line-height: 1;
}

.results {
  margin-top: 1.15rem;
  display: none;
}

.results.is-visible {
  display: block;
}

.summary {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-bottom: 0.85rem;
}

.summary-chip {
  padding: 0.45rem 0.8rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-weight: 600;
  font-size: 0.88rem;
}

.summary-chip.gain {
  background: var(--warn-soft);
  color: var(--warn);
}

.result-list {
  display: grid;
  gap: 0.65rem;
}

.badge {
  display: inline-flex;
  margin-top: 0.3rem;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 0.78rem;
  font-weight: 600;
}

.badge.loss {
  background: var(--warn-soft);
  color: var(--warn);
}

.progress-wrap {
  display: none;
  margin-top: 1rem;
}

.progress-wrap.is-visible {
  display: block;
}

.progress-track {
  height: 0.4rem;
  border-radius: 999px;
  background: var(--bg-soft);
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  width: 0;
  border-radius: inherit;
  background: var(--accent);
  transition: width 0.25s ease;
}

.progress-label {
  margin-top: 0.4rem;
  font-size: 0.88rem;
  color: var(--muted);
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 1.25rem;
  transform: translateX(-50%) translateY(120%);
  background: var(--ink);
  color: #fff;
  padding: 0.75rem 1.05rem;
  border-radius: 999px;
  z-index: 60;
  opacity: 0;
  transition: transform 0.25s ease, opacity 0.25s ease;
  max-width: min(92vw, 420px);
  text-align: center;
  font-size: 0.94rem;
}

.toast.is-visible {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

.section {
  width: min(100% - 2rem, var(--max));
  margin: 0 auto;
  padding: 3rem 0 1rem;
}

.section h2 {
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 3.2vw, 2rem);
  letter-spacing: -0.02em;
  font-weight: 600;
  margin: 0 0 0.5rem;
}

.section-lead {
  margin: 0 0 1.4rem;
  color: var(--muted);
  max-width: 38rem;
}

.feature-flow {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.85rem;
}

.flow-step {
  padding: 1.15rem 1.05rem;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--line);
}

.flow-step .step-num {
  font-family: var(--font-display);
  font-size: 1.35rem;
  color: var(--accent);
  margin-bottom: 0.45rem;
}

.flow-step h3 {
  margin: 0 0 0.35rem;
  font-size: 1.05rem;
}

.flow-step p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.format-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.format-pill {
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--line);
  font-weight: 600;
  font-size: 0.86rem;
  color: var(--muted);
}

.tutorial-list {
  display: grid;
  gap: 0.75rem;
  counter-reset: step;
}

.tutorial-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.9rem;
  align-items: start;
  padding: 1rem 1.05rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.tutorial-item::before {
  counter-increment: step;
  content: counter(step);
  width: 1.85rem;
  height: 1.85rem;
  border-radius: 999px;
  display: grid;
  place-items: center;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-weight: 700;
  font-size: 0.9rem;
  margin-top: 0.1rem;
}

.tutorial-item h3 {
  margin: 0 0 0.25rem;
  font-size: 1.02rem;
}

.tutorial-item p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.faq-list {
  display: grid;
  gap: 0.65rem;
}

.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  overflow: hidden;
}

.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 1rem 1.1rem;
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  color: var(--accent);
  font-size: 1.2rem;
  font-weight: 500;
  line-height: 1;
}

.faq-item[open] summary::after {
  content: "–";
}

.faq-item summary:hover {
  background: #fafcfd;
}

.faq-body {
  padding: 0 1.1rem 1.05rem;
  color: var(--muted);
  font-size: 0.96rem;
}

.faq-body p {
  margin: 0 0 0.65rem;
}

.faq-body p:last-child {
  margin-bottom: 0;
}

.site-footer {
  width: min(100% - 2rem, var(--max));
  margin: 2rem auto 0;
  padding: 1.5rem 0 2.5rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.65rem;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-size: 0.9rem;
}

@media (max-width: 900px) {
  .controls-grid,
  .feature-flow {
    grid-template-columns: 1fr 1fr;
  }

  .mode-tabs {
    grid-template-columns: 1fr;
  }

  .nav-links {
    display: none;
  }
}

@media (max-width: 640px) {
  .hero {
    padding-top: 2rem;
  }

  .controls-grid,
  .feature-flow {
    grid-template-columns: 1fr;
  }

  .queue-item,
  .result-card {
    grid-template-columns: 52px 1fr;
  }

  .queue-item .queue-remove,
  .result-card .btn {
    grid-column: 1 / -1;
    justify-self: start;
  }

  .controls-actions {
    align-items: stretch;
  }

  .controls-actions .btn {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .toast,
  .btn,
  .mode-tab,
  .dropzone {
    transition: none;
  }
}