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

:root {
  --bg: #0f172a;
  --bg-soft: #020617;
  --card: #020617;
  --card-soft: #020617;
  --accent: #38bdf8;
  --accent-soft: rgba(56, 189, 248, 0.08);
  --accent-strong: #0ea5e9;
  --text: #e5e7eb;
  --text-soft: #9ca3af;
  --danger: #f97373;
  --border: rgba(148, 163, 184, 0.55);
  --radius-lg: 1.2rem;
  --radius-xl: 1.6rem;
  --shadow-soft: 0 24px 60px rgba(15, 23, 42, 0.55);
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", sans-serif;
  line-height: 1.6;
  background: radial-gradient(circle at top, #1e293b 0, #020617 45%, #000 100%);
  color: var(--text);
  min-height: 100vh;
}

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

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

/* layout */

.page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* header + brand */

.app-header {
  padding: 1.3rem 0 0.7rem;
}

.app-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.brand__logo {
  width: 38px;
  height: 38px;
  border-radius: 1.1rem;
  background: radial-gradient(circle at 25% 10%, #38bdf8, #0ea5e9 45%, #0f172a 100%);
  box-shadow: 0 14px 40px rgba(56, 189, 248, 0.75);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  letter-spacing: 0.08em;
  font-size: 0.9rem;
  color: #e5f3ff;
}

.brand__text-title {
  font-size: 1.15rem;
  font-weight: 600;
}

.brand__text-sub {
  font-size: 0.8rem;
  color: var(--text-soft);
}

/* header nav */

.app-nav {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.82rem;
}

.app-nav a {
  padding-bottom: 0.15rem;
  border-bottom: 1px solid transparent;
  color: var(--text-soft);
}

.app-nav a:hover {
  color: var(--accent);
  border-bottom-color: rgba(56, 189, 248, 0.4);
}

.app-nav .app-nav-active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* login page */

.main-center {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2.5rem 1.5rem 3rem;
}

.login-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  gap: 2.5rem;
  align-items: center;
  width: 100%;
  max-width: 1040px;
}

.card {
  background: radial-gradient(circle at top, #020617 0, #020617 55%, #020617 100%);
  border-radius: var(--radius-xl);
  padding: 2rem 2.1rem 2rem;
  border: 1px solid rgba(148, 163, 184, 0.5);
  box-shadow: var(--shadow-soft);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  inset: -40%;
  background:
    radial-gradient(circle at 0 0, rgba(56, 189, 248, 0.16), transparent 55%),
    radial-gradient(circle at 100% 0, rgba(94, 234, 212, 0.16), transparent 50%);
  opacity: 0.7;
  pointer-events: none;
}

.card__inner {
  position: relative;
  z-index: 1;
}

.card--ghost {
  border-style: dashed;
  border-color: rgba(148, 163, 184, 0.6);
  background: linear-gradient(135deg, rgba(15, 23, 42, 0.85), rgba(15, 23, 42, 0.98));
}

/* text */

h1 {
  font-size: clamp(1.8rem, 2.8vw + 0.6rem, 2.4rem);
  letter-spacing: -0.03em;
  margin-bottom: 0.4rem;
}

p.lead {
  font-size: 0.98rem;
  color: var(--text-soft);
  max-width: 30rem;
  margin-bottom: 1.4rem;
}

.mono {
  font-family: "SF Mono", ui-monospace, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

/* form */

.form {
  display: grid;
  gap: 1.1rem;
  margin-top: 0.7rem;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.86rem;
}

.field label {
  color: var(--text-soft);
  font-size: 0.8rem;
}

.field input,
.field textarea {
  border-radius: 0.9rem;
  border: 1px solid rgba(148, 163, 184, 0.9);
  padding: 0.7rem 0.75rem;
  font: inherit;
  background: rgba(15, 23, 42, 0.9);
  color: var(--text);
  outline: none;
  transition: border-color 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}

.field textarea {
  min-height: 120px;
  resize: vertical;
}

.field input::placeholder,
.field textarea::placeholder {
  color: #6b7280;
}

.field input:focus,
.field textarea:focus {
  border-color: var(--accent);
  background: rgba(15, 23, 42, 1);
  box-shadow: 0 0 0 1px rgba(56, 189, 248, 0.45);
}

.form-hint {
  font-size: 0.78rem;
  color: var(--text-soft);
}

/* error message */

.alert {
  font-size: 0.8rem;
  border-radius: 0.9rem;
  border: 1px solid rgba(248, 113, 113, 0.7);
  background: linear-gradient(135deg, rgba(30, 64, 175, 0.65), rgba(30, 64, 175, 0.3));
  color: #fee2e2;
  padding: 0.55rem 0.75rem;
  margin-top: 0.7rem;
}

/* buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.65rem 1.25rem;
  border-radius: 999px;
  font-size: 0.88rem;
  border: 1px solid transparent;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  transition: all 0.18s ease;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #0b1120;
  font-weight: 600;
  box-shadow: 0 18px 45px rgba(56, 189, 248, 0.55);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 22px 55px rgba(56, 189, 248, 0.7);
}

.btn-ghost {
  border-color: rgba(148, 163, 184, 0.7);
  color: var(--text-soft);
}

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* main content */

.main-content {
  flex: 1;
  padding: 1.4rem 0 3.2rem;
}

/* panel */

.panel {
  border-radius: var(--radius-xl);
  padding: 1.7rem 1.8rem 1.9rem;
  border: 1px solid rgba(148, 163, 184, 0.6);
  background: radial-gradient(circle at top left, rgba(15, 23, 42, 0.9), #020617 55%);
  box-shadow: var(--shadow-soft);
}

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 1.4rem;
}

.panel-header h2 {
  font-size: 1.2rem;
  letter-spacing: -0.02em;
}

.panel-header span {
  font-size: 0.78rem;
  color: var(--text-soft);
}

/* folder layout */

.folder-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.6fr);
  gap: 1.6rem;
  align-items: flex-start;
}

.folder-sidebar {
  border-right: 1px solid rgba(30, 41, 59, 0.9);
  padding-right: 1.2rem;
}

.folder-sidebar h3 {
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.folder-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  font-size: 0.85rem;
}

.folder-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.35rem 0.4rem;
  border-radius: 0.6rem;
  cursor: pointer;
  border: 1px solid transparent;
  color: var(--text-soft);
}

.folder-link span {
  font-size: 0.74rem;
  opacity: 0.9;
}

.folder-link:hover {
  color: var(--accent);
  border-color: rgba(56, 189, 248, 0.5);
  background: rgba(15, 23, 42, 0.9);
}

.folder-link-active {
  border-color: var(--accent);
  background: rgba(37, 99, 235, 0.1);
  color: var(--accent);
}

/* file list */

.files-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 0.9fr);
  font-size: 0.86rem;
  border-radius: 1rem;
  border: 1px solid rgba(51, 65, 85, 0.8);
  background: radial-gradient(circle at top left, rgba(15, 23, 42, 0.85), rgba(15, 23, 42, 0.98));
  overflow: hidden;
}

.files-grid-header,
.files-grid-row {
  display: contents;
}

.files-grid-header div {
  padding: 0.7rem 0.9rem;
  background: rgba(15, 23, 42, 0.98);
  font-size: 0.76rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-soft);
  border-bottom: 1px solid rgba(51, 65, 85, 0.9);
}

.files-grid-row div {
  padding: 0.6rem 0.9rem;
  border-bottom: 1px solid rgba(30, 41, 59, 0.9);
}

.files-grid-row:nth-child(even) div {
  background: rgba(15, 23, 42, 0.96);
}

.file-name a {
  color: var(--accent);
}

.file-name a:hover {
  text-decoration: underline;
}

/* detail view */

.detail-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
  gap: 2rem;
  align-items: flex-start;
}

.detail-image {
  border-radius: 1.2rem;
  border: 1px solid rgba(148, 163, 184, 0.6);
  overflow: hidden;
  background: radial-gradient(circle at top, #0f172a, #020617 70%);
}

.detail-image img {
  width: 100%;
  height: auto;
}

.detail-meta {
  font-size: 0.86rem;
  color: var(--text-soft);
}

.detail-meta h2 {
  font-size: 1.1rem;
  margin-bottom: 0.3rem;
}

/* audio */

.audio-wrapper {
  border-radius: 1rem;
  border: 1px solid rgba(148, 163, 184, 0.6);
  background: rgba(15, 23, 42, 0.96);
  padding: 1rem;
}

/* footer */

footer {
  padding: 0 0 1.6rem;
  font-size: 0.78rem;
  color: var(--text-soft);
}

footer .container {
  border-top: 1px solid rgba(30, 41, 59, 0.9);
  padding-top: 0.9rem;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

/* responsive */

@media (max-width: 900px) {
  .login-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .detail-layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .files-grid {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.9fr);
  }

  .folder-layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .folder-sidebar {
    border-right: none;
    border-bottom: 1px solid rgba(30, 41, 59, 0.9);
    padding-right: 0;
    padding-bottom: 1rem;
  }
}

@media (max-width: 640px) {
  .container {
    padding: 0 1.2rem;
  }

  .panel {
    padding: 1.4rem 1.4rem 1.6rem;
  }

  .files-grid {
    font-size: 0.8rem;
  }

  .app-header__inner {
    flex-direction: column;
    align-items: flex-start;
  }
}