:root {
  --ink: #1c2430;
  --ink-soft: #3d4a5c;
  --muted: #6b778a;
  --paper: #eef2f7;
  --surface: rgba(255, 255, 255, 0.78);
  --line: rgba(28, 36, 48, 0.12);
  --accent: #d97706;
  --accent-deep: #b45309;
  --navy: #2a4a7a;
  --navy-deep: #1a3258;
  --sky: #4a7ab5;
  --error: #b42318;
  --error-bg: #fef3f2;
  --shadow: 0 18px 50px rgba(28, 36, 48, 0.1);
  --radius: 14px;
  --font-display: "Noto Serif SC", "Songti SC", serif;
  --font-body: "Sora", "PingFang SC", "Microsoft YaHei", sans-serif;
}

*,
*::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: var(--paper);
  line-height: 1.6;
  position: relative;
}

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

.page-bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(900px 520px at 10% -8%, rgba(42, 74, 122, 0.2), transparent 60%),
    radial-gradient(700px 480px at 94% 6%, rgba(217, 119, 6, 0.12), transparent 55%),
    linear-gradient(165deg, #e4ebf4 0%, #eef2f7 45%, #e8eef5 100%);
}

.page-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0.4;
  background-image:
    linear-gradient(rgba(28, 36, 48, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(28, 36, 48, 0.035) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: linear-gradient(to bottom, black 0%, transparent 85%);
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.25rem 1.5rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
}

.brand-mark {
  width: 1.1rem;
  height: 1.1rem;
  border-radius: 3px;
  background: linear-gradient(135deg, var(--sky), var(--navy-deep));
  box-shadow: inset 0 0 0 2px rgba(255, 255, 255, 0.22);
  animation: mark-pulse 4s ease-in-out infinite;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.2rem;
  letter-spacing: 0.08em;
}

.nav {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-size: 0.95rem;
  color: var(--ink-soft);
}

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

.nav-cta {
  padding: 0.45rem 0.95rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.55);
  transition: border-color 0.2s ease, background 0.2s ease;
}

.nav-cta:hover {
  border-color: var(--navy);
  background: #fff;
}

.hero {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 2.5rem;
  align-items: center;
  min-height: calc(100vh - 5.5rem);
}

.brand-hero {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 6vw, 4rem);
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--navy-deep);
  line-height: 1.1;
  animation: rise-in 0.8s ease both;
}

.hero h1 {
  margin: 0 0 1rem;
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 3.2vw, 2.15rem);
  font-weight: 500;
  line-height: 1.35;
  color: var(--ink);
  animation: rise-in 0.8s ease 0.08s both;
}

.hero-lead {
  margin: 0 0 1.75rem;
  max-width: 32rem;
  color: var(--ink-soft);
  font-size: 1.05rem;
  animation: rise-in 0.8s ease 0.16s both;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  animation: rise-in 0.8s ease 0.24s both;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.78rem 1.35rem;
  border-radius: 10px;
  border: 1px solid transparent;
  font-family: inherit;
  font-size: 0.98rem;
  font-weight: 500;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease, border-color 0.2s ease;
}

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

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

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

.btn-ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--ink-soft);
}

.btn-ghost:hover {
  border-color: var(--navy);
  color: var(--ink);
  background: rgba(255, 255, 255, 0.5);
}

.btn-block {
  width: 100%;
}

.hero-visual {
  display: flex;
  justify-content: center;
  animation: float-in 1s ease 0.2s both;
}

.board {
  width: min(100%, 340px);
  padding: 1.25rem 1.2rem 1.4rem;
  border-radius: 18px;
  background:
    linear-gradient(165deg, rgba(255, 255, 255, 0.65), transparent 45%),
    linear-gradient(180deg, #2f4f82, #1a3258);
  box-shadow: 0 24px 48px rgba(26, 50, 88, 0.28);
  color: #e8eef6;
}

.board-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.1rem;
}

.board-date {
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: 0.06em;
}

.board-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #fbbf24;
  box-shadow: 0 0 0 4px rgba(251, 191, 36, 0.2);
  animation: mark-pulse 2.8s ease-in-out infinite;
}

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

.task {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 0.65rem;
  padding: 0.7rem 0.8rem;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.08);
  font-size: 0.9rem;
}

.task i {
  width: 14px;
  height: 14px;
  border-radius: 4px;
  border: 1.5px solid rgba(255, 255, 255, 0.45);
  display: block;
}

.task em {
  font-style: normal;
  opacity: 0.65;
  font-size: 0.78rem;
}

.task.done {
  opacity: 0.7;
}

.task.done i {
  background: #34d399;
  border-color: #34d399;
  position: relative;
}

.task.done i::after {
  content: "";
  position: absolute;
  left: 3px;
  top: 1px;
  width: 4px;
  height: 7px;
  border: solid #0f2a22;
  border-width: 0 1.5px 1.5px 0;
  transform: rotate(40deg);
}

.task.done span {
  text-decoration: line-through;
}

.task.active {
  background: rgba(251, 191, 36, 0.16);
  outline: 1px solid rgba(251, 191, 36, 0.35);
}

.task.active i {
  border-color: #fbbf24;
  animation: mark-pulse 2s ease-in-out infinite;
}

.board-bar {
  margin-top: 1.15rem;
  height: 6px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  overflow: hidden;
}

.board-bar span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #fbbf24, #f59e0b);
  animation: bar-grow 1.4s ease 0.4s both;
}

.section {
  max-width: 1100px;
  margin: 0 auto;
  padding: 3.5rem 1.5rem;
}

.section h2 {
  margin: 0 0 0.65rem;
  font-family: var(--font-display);
  font-size: clamp(1.45rem, 2.5vw, 1.85rem);
  font-weight: 700;
}

.section-lead {
  margin: 0 0 2rem;
  max-width: 36rem;
  color: var(--ink-soft);
}

.feature-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem 2rem;
}

.feature-list h3 {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--navy-deep);
}

.feature-list p {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
}

.flow {
  border-top: 1px solid var(--line);
}

.flow-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.9rem;
  max-width: 36rem;
  counter-reset: step;
}

.flow-list li {
  position: relative;
  padding: 0.85rem 1rem 0.85rem 3.2rem;
  border-left: 2px solid rgba(42, 74, 122, 0.25);
  color: var(--ink-soft);
  counter-increment: step;
}

.flow-list li::before {
  content: counter(step);
  position: absolute;
  left: 0.85rem;
  top: 0.95rem;
  width: 1.4rem;
  height: 1.4rem;
  border-radius: 50%;
  background: var(--navy);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

.flow-list strong {
  color: var(--ink);
  margin-right: 0.35rem;
}

.about {
  padding-bottom: 5rem;
  border-top: 1px solid var(--line);
}

.site-footer {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem 2.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  justify-content: space-between;
  align-items: center;
  color: var(--muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--line);
}

.footer-brand {
  margin: 0;
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  color: var(--ink-soft);
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.site-footer a:hover {
  color: var(--navy-deep);
  border-bottom-color: var(--navy);
}

/* Login */
.login-page {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

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

.login-panel {
  width: min(100%, 420px);
  padding: 2.25rem 2rem;
  background: var(--surface);
  backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  animation: rise-in 0.55s ease both;
}

.login-brand {
  margin: 0 0 0.35rem;
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--navy-deep);
}

.login-panel h1 {
  margin: 0 0 0.5rem;
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 500;
}

.login-lead {
  margin: 0 0 1.5rem;
  color: var(--muted);
  font-size: 0.95rem;
}

.login-form {
  display: grid;
  gap: 1rem;
}

.field {
  display: grid;
  gap: 0.4rem;
}

.field span {
  font-size: 0.88rem;
  color: var(--ink-soft);
  font-weight: 500;
}

.field input {
  width: 100%;
  padding: 0.8rem 0.9rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.9);
  font: inherit;
  color: var(--ink);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.field input::placeholder {
  color: #9aa5b5;
}

.field input:focus {
  border-color: var(--navy);
  box-shadow: 0 0 0 3px rgba(42, 74, 122, 0.15);
}

.login-error {
  margin: 0;
  padding: 0.65rem 0.8rem;
  border-radius: 8px;
  background: var(--error-bg);
  color: var(--error);
  font-size: 0.92rem;
  animation: shake 0.35s ease;
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float-in {
  from {
    opacity: 0;
    transform: translateY(24px) scale(0.96);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes mark-pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.08); opacity: 0.85; }
}

@keyframes bar-grow {
  from { width: 0; }
  to { width: 42%; }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

@media (max-width: 860px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-top: 1.5rem;
    gap: 2rem;
  }

  .hero-visual {
    order: -1;
  }

  .board {
    width: min(100%, 300px);
  }

  .feature-list {
    grid-template-columns: 1fr;
    gap: 1.35rem;
  }
}

@media (max-width: 520px) {
  .site-header {
    padding: 1rem 1.1rem;
  }

  .nav {
    gap: 0.75rem;
  }

  .nav a:not(.nav-cta) {
    display: none;
  }

  .login-panel {
    padding: 1.75rem 1.25rem;
  }

  .site-footer {
    flex-direction: column;
    align-items: flex-start;
  }
}