/*
 * IMGSLIM Design System
 * File: /css/style.css
 */

:root {
  /* Brand */
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-primary-soft: #dbeafe;
  --color-accent: #14b8a6;
  --color-accent-soft: #ccfbf1;

  /* Surface */
  --color-bg: #f7f9fc;
  --color-bg-strong: #eef4ff;
  --color-surface: #ffffff;
  --color-surface-soft: #f8fafc;
  --color-muted: #edf2f7;

  /* Text */
  --color-text: #0f172a;
  --color-text-sub: #475569;
  --color-text-muted: #94a3b8;
  --color-white: #ffffff;

  /* Border */
  --color-border: #e2e8f0;
  --color-border-strong: #cbd5e1;

  /* Status */
  --color-success: #16a34a;
  --color-success-bg: #dcfce7;
  --color-success-text: #166534;
  --color-error-bg: #fee2e2;
  --color-error-text: #991b1b;
  --color-warning-bg: #fff7ed;
  --color-warning-text: #9a3412;
  --color-info-bg: #e0f2fe;
  --color-info-text: #075985;

  /* Font */
  --font-sans: 'Inter', 'Noto Sans KR', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --font-mono: 'SF Mono', Consolas, monospace;

  /* Font size */
  --fs-xs: 12px;
  --fs-sm: 13px;
  --fs-base: 15px;
  --fs-md: 16px;
  --fs-lg: 20px;
  --fs-xl: 28px;
  --fs-2xl: clamp(32px, 4vw, 58px);

  /* Layout */
  --container-sm: 760px;
  --container-md: 1040px;
  --container-lg: 1200px;
  --header-height: 76px;
  --layout-gap: 28px;

  /* Spacing */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 72px;

  /* Radius / Shadow */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-pill: 999px;
  --shadow-sm: 0 2px 10px rgba(15, 23, 42, .06);
  --shadow-md: 0 12px 32px rgba(15, 23, 42, .10);
  --shadow-lg: 0 24px 70px rgba(37, 99, 235, .18);

  /* Motion */
  --transition-fast: 150ms ease;
  --transition-base: 220ms ease;
}

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

html {
  overflow-y: scroll;
  scrollbar-gutter: stable;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-md);
  color: var(--color-text);
  background:
    radial-gradient(circle at top left, rgba(37, 99, 235, .10), transparent 32rem),
    linear-gradient(180deg, #fbfdff 0%, var(--color-bg) 42%, #fff 100%);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

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

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

::selection {
  color: var(--color-white);
  background: var(--color-primary);
}

.container {
  width: 100%;
  max-width: var(--container-lg);
  margin: 0 auto;
  padding: 0 var(--space-5);
}

.container-narrow {
  max-width: var(--container-md);
}

.section-pad {
  padding: var(--space-8) 0;
}

.section-pad-sm {
  padding: var(--space-7) 0;
}

.is-hidden {
  display: none !important;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  min-height: var(--header-height);
  border-bottom: 1px solid rgba(226, 232, 240, .78);
  background: rgba(255, 255, 255, .78);
  backdrop-filter: blur(18px);
}

.header-container {
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
}

.brand-mark {
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  color: var(--color-white);
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  box-shadow: 0 10px 24px rgba(37, 99, 235, .22);
}

.brand-text {
  display: grid;
  line-height: 1.15;
}

.brand-text strong {
  font-size: var(--fs-md);
  letter-spacing: -.02em;
}

.brand-text small {
  font-size: var(--fs-xs);
  font-weight: 800;
  color: var(--color-text-muted);
  letter-spacing: .08em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.nav-link {
  padding: 9px 13px;
  border-radius: var(--radius-pill);
  color: var(--color-text-sub);
  font-size: var(--fs-sm);
  font-weight: 800;
  letter-spacing: .04em;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
  background: var(--color-primary-soft);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  background: var(--color-surface);
}

.hero-section {
  position: relative;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 84% 16%, rgba(20, 184, 166, .24), transparent 23rem),
    radial-gradient(circle at 20% 74%, rgba(37, 99, 235, .16), transparent 26rem);
}

.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(320px, .98fr);
  gap: var(--space-7);
  align-items: center;
}

.eyebrow,
.section-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  width: fit-content;
  padding: 7px 12px;
  border: 1px solid rgba(37, 99, 235, .16);
  border-radius: var(--radius-pill);
  color: var(--color-primary);
  background: rgba(219, 234, 254, .72);
  font-size: var(--fs-sm);
  font-weight: 800;
}

.hero-content h1 {
  margin: var(--space-4) 0 var(--space-4);
  font-size: var(--fs-2xl);
  line-height: 1.08;
  letter-spacing: -.055em;
}

.hero-copy {
  max-width: 620px;
  margin: 0 0 var(--space-6);
  color: var(--color-text-sub);
  font-size: clamp(17px, 1.7vw, 20px);
}

.hero-actions,
.result-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.hero-metrics {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
  margin-top: var(--space-6);
}

.hero-metrics div {
  min-width: 118px;
  padding: var(--space-4);
  border: 1px solid rgba(226, 232, 240, .82);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, .72);
  box-shadow: var(--shadow-sm);
}

.hero-metrics strong {
  display: block;
  font-size: var(--fs-lg);
  line-height: 1.2;
}

.hero-metrics span {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  font-weight: 700;
}

.hero-panel {
  position: relative;
  min-height: 410px;
  padding: var(--space-6);
  border: 1px solid rgba(226, 232, 240, .88);
  border-radius: var(--radius-xl);
  background: linear-gradient(145deg, rgba(255, 255, 255, .88), rgba(248, 250, 252, .78));
  box-shadow: var(--shadow-lg);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: var(--space-4);
}

.preview-card {
  padding: var(--space-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

.preview-card span {
  color: var(--color-text-muted);
  font-size: var(--fs-xs);
  font-weight: 900;
  letter-spacing: .1em;
  text-transform: uppercase;
}

.preview-card strong {
  display: block;
  margin-top: var(--space-3);
  font-size: var(--fs-lg);
}

.preview-image {
  height: 150px;
  margin-top: var(--space-3);
  border-radius: var(--radius-md);
  background:
    linear-gradient(135deg, transparent 48%, rgba(37, 99, 235, .12) 49% 51%, transparent 52%),
    linear-gradient(160deg, #e2e8f0, #f8fafc);
}

.preview-image.slim {
  height: 118px;
  background:
    linear-gradient(135deg, transparent 48%, rgba(20, 184, 166, .14) 49% 51%, transparent 52%),
    linear-gradient(160deg, #dbeafe, #ccfbf1);
}

.preview-arrow {
  width: 46px;
  height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-pill);
  color: var(--color-primary);
  background: var(--color-primary-soft);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 42px;
  padding: 10px 18px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-size: var(--fs-base);
  font-weight: 800;
  text-decoration: none;
  transition: transform var(--transition-fast), background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  color: var(--color-white);
  background: var(--color-primary);
  box-shadow: 0 14px 30px rgba(37, 99, 235, .24);
}

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

.btn-success {
  color: var(--color-white);
  background: var(--color-success);
}

.btn-ghost {
  color: var(--color-text);
  background: var(--color-white);
  border-color: var(--color-border);
}

.btn-outline {
  color: var(--color-primary);
  background: transparent;
  border-color: var(--color-border-strong);
}

.btn-sm {
  min-height: 34px;
  padding: 6px 12px;
  font-size: var(--fs-sm);
}

.btn-lg {
  min-height: 50px;
  padding: 12px 22px;
}

.btn-xl {
  min-height: 58px;
  padding: 14px 28px;
  font-size: var(--fs-md);
}

.section-header {
  max-width: 760px;
  margin: 0 auto var(--space-6);
  text-align: center;
}

.section-header h2 {
  margin: var(--space-3) 0 var(--space-2);
  font-size: clamp(28px, 3vw, 42px);
  line-height: 1.18;
  letter-spacing: -.04em;
}

.section-header p {
  margin: 0;
  color: var(--color-text-sub);
}

.app-card,
.feature-card,
.setting-card,
.faq-list details {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background: rgba(255, 255, 255, .86);
  box-shadow: var(--shadow-md);
}

.app-card {
  padding: var(--space-5);
}

.drop-zone {
  display: grid;
  justify-items: center;
  gap: var(--space-3);
  padding: var(--space-8) var(--space-5);
  border: 2px dashed var(--color-border-strong);
  border-radius: var(--radius-xl);
  text-align: center;
  background:
    linear-gradient(180deg, rgba(248, 250, 252, .92), rgba(255, 255, 255, .96));
  transition: border-color var(--transition-base), background var(--transition-base), transform var(--transition-base);
}

.drop-zone:hover,
.drop-zone.is-dragover {
  border-color: var(--color-primary);
  background: var(--color-primary-soft);
  transform: translateY(-2px);
}

.drop-zone.is-reject {
  border-color: var(--color-error-text);
  background: var(--color-error-bg);
}

.drop-icon {
  width: 74px;
  height: 74px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 24px;
  color: var(--color-primary);
  background: var(--color-primary-soft);
  font-size: 34px;
}

.drop-zone strong {
  font-size: var(--fs-lg);
  letter-spacing: -.02em;
}

.drop-zone small {
  color: var(--color-text-muted);
}

.file-list,
.settings-grid,
.submit-area,
.processing-panel,
.results-panel {
  margin-top: var(--space-5);
}

.panel-head,
.setting-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}

.panel-head h3,
.setting-head h3 {
  margin: 0;
  font-size: var(--fs-lg);
  letter-spacing: -.02em;
}

.count-badge,
.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 28px;
  padding: 2px 8px;
  border-radius: var(--radius-pill);
  color: var(--color-primary);
  background: var(--color-primary-soft);
  font-size: var(--fs-xs);
  font-weight: 900;
}

.file-list-group {
  display: grid;
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.file-item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface-soft);
}

.file-icon {
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-primary);
  background: var(--color-primary-soft);
}

.file-meta strong {
  display: block;
  word-break: break-all;
}

.file-meta small {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
}

.icon-btn {
  width: 36px;
  height: 36px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  color: var(--color-error-text);
  background: var(--color-white);
}

.settings-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-4);
}

.setting-card {
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
}

.setting-card-wide {
  grid-column: 1 / -1;
}

.setting-icon {
  width: 38px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-primary);
  background: var(--color-primary-soft);
}

.quality-display {
  margin: var(--space-5) 0 var(--space-3);
  font-size: 38px;
  font-weight: 900;
  letter-spacing: -.05em;
}

.range-input {
  width: 100%;
  accent-color: var(--color-primary);
}

.range-labels {
  display: flex;
  justify-content: space-between;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  font-weight: 700;
}

.field-with-unit {
  display: flex;
  align-items: center;
  margin: var(--space-5) 0 var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-white);
  overflow: hidden;
}

.field-with-unit input {
  width: 100%;
  min-height: 48px;
  padding: 0 var(--space-4);
  border: 0;
  outline: none;
  font-weight: 800;
}

.field-with-unit span {
  padding: 0 var(--space-4);
  color: var(--color-text-muted);
  font-weight: 800;
}

.preset-group,
.format-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.preset-btn,
.format-option {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  transition: border-color var(--transition-fast), background var(--transition-fast), transform var(--transition-fast);
}

.preset-btn {
  min-height: 36px;
  padding: 0 13px;
  color: var(--color-text-sub);
  font-weight: 800;
}

.preset-btn.active,
.preset-btn:hover,
.format-option.selected,
.format-option:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-soft);
}

.format-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: var(--space-4);
}

.format-option {
  display: grid;
  gap: var(--space-1);
  min-height: 92px;
  padding: var(--space-4);
  text-align: left;
}

.format-option strong {
  font-size: var(--fs-lg);
}

.format-option span {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  font-weight: 700;
}

.submit-area {
  text-align: center;
}

.processing-panel,
.results-panel {
  text-align: center;
}

.processing-panel {
  padding: var(--space-7) var(--space-5);
}

.spinner {
  width: 54px;
  height: 54px;
  margin: 0 auto var(--space-4);
  border: 5px solid var(--color-primary-soft);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 900ms linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.progress-track {
  height: 12px;
  margin: var(--space-5) auto var(--space-2);
  border-radius: var(--radius-pill);
  background: var(--color-muted);
  overflow: hidden;
}

.progress-bar {
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transition: width var(--transition-base);
}

.result-hero {
  padding-top: var(--space-2);
}

.success-icon {
  width: 66px;
  height: 66px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-pill);
  color: var(--color-success);
  background: var(--color-success-bg);
  font-size: 32px;
}

.result-hero h3 {
  margin: var(--space-3) 0 0;
  font-size: var(--fs-xl);
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-3);
  margin: var(--space-5) 0;
}

.summary-grid div {
  padding: var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface-soft);
}

.summary-grid span {
  display: block;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  font-weight: 800;
}

.summary-grid strong {
  display: block;
  margin-top: var(--space-1);
  font-size: var(--fs-lg);
}

.group-download-area {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-2);
  margin-bottom: var(--space-5);
}

.table-wrap {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.result-table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
  text-align: left;
  background: var(--color-white);
}

.result-table th,
.result-table td {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border);
  vertical-align: middle;
}

.result-table th {
  color: var(--color-text-sub);
  background: var(--color-surface-soft);
  font-size: var(--fs-sm);
  font-weight: 900;
}

.result-table tr:last-child td {
  border-bottom: 0;
}

.table-note {
  color: var(--color-warning-text);
  background: var(--color-warning-bg);
}

.result-actions {
  justify-content: center;
  margin-top: var(--space-5);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--space-4);
}

.feature-card {
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
}

.feature-card i {
  width: 48px;
  height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-lg);
  color: var(--color-primary);
  background: var(--color-primary-soft);
  font-size: 24px;
}

.feature-card h3 {
  margin: var(--space-4) 0 var(--space-2);
  font-size: var(--fs-lg);
  letter-spacing: -.02em;
}

.feature-card p {
  margin: 0;
  color: var(--color-text-sub);
}

.faq-list {
  display: grid;
  gap: var(--space-3);
}

.faq-list details {
  padding: var(--space-4) var(--space-5);
  box-shadow: var(--shadow-sm);
}

.faq-list summary {
  cursor: pointer;
  font-weight: 900;
}

.faq-list p {
  margin: var(--space-3) 0 0;
  color: var(--color-text-sub);
}

.alert {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--fs-base);
  margin-bottom: var(--space-4);
}

.alert-success {
  color: var(--color-success-text);
  background: var(--color-success-bg);
  border: 1px solid #bbf7d0;
}

.alert-error,
.alert-danger {
  color: var(--color-error-text);
  background: var(--color-error-bg);
  border: 1px solid #fecaca;
}

.alert-warning {
  color: var(--color-warning-text);
  background: var(--color-warning-bg);
  border: 1px solid #fed7aa;
}

.site-footer {
  margin-top: var(--space-7);
  padding: var(--space-7) 0;
  color: var(--color-text-sub);
  background: #0f172a;
}

.site-footer .brand-text strong,
.site-footer .footer-links a {
  color: var(--color-white);
}

.footer-grid {
  display: flex;
  justify-content: space-between;
  gap: var(--space-5);
}

.footer-brand {
  margin-bottom: var(--space-3);
}

.footer-links {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  align-items: center;
}

@media (max-width: 1024px) {
  .hero-grid,
  .features-grid {
    grid-template-columns: 1fr 1fr;
  }

  .hero-panel {
    grid-column: 1 / -1;
  }
}

@media (max-width: 760px) {
  :root {
    --header-height: 68px;
  }

  .container {
    padding: 0 var(--space-4);
  }

  .section-pad {
    padding: var(--space-7) 0;
  }

  .site-nav {
    position: absolute;
    left: var(--space-4);
    right: var(--space-4);
    top: calc(var(--header-height) - 4px);
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: var(--space-3);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-white);
    box-shadow: var(--shadow-md);
  }

  .site-nav.is-open {
    display: flex;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .hero-grid,
  .settings-grid,
  .features-grid,
  .summary-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero-panel {
    min-height: auto;
    grid-template-columns: 1fr;
  }

  .preview-arrow {
    transform: rotate(90deg);
    justify-self: center;
  }

  .format-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .app-card {
    padding: var(--space-4);
  }

  .drop-zone {
    padding: var(--space-7) var(--space-4);
  }
}

@media (max-width: 480px) {
  .hero-actions,
  .result-actions {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .format-grid {
    grid-template-columns: 1fr;
  }

  .file-item {
    grid-template-columns: auto 1fr;
  }

  .file-item .icon-btn {
    grid-column: 1 / -1;
    width: 100%;
  }
}