/* =========================================================
   S-AES LAB — MAIN STYLESHEET
   Design tokens: glassmorphism, gradient background, premium academic feel
   ========================================================= */

:root {
  --c-primary: #2563EB;
  --c-primary-light: #4F8DFF;
  --c-secondary: #0F172A;
  --c-accent: #38BDF8;
  --c-success: #10B981;
  --c-warning: #F59E0B;
  --c-danger: #EF4444;

  --c-bg-body: #EEF4FF;
  --c-glass-bg: rgba(255, 255, 255, 0.62);
  --c-glass-border: rgba(255, 255, 255, 0.55);
  --c-text-main: #10192E;
  --c-text-muted: #5B6B8C;

  --radius-card: 20px;
  --radius-sm: 12px;
  --shadow-soft: 0 10px 40px rgba(15, 23, 42, 0.08);
  --shadow-strong: 0 20px 60px rgba(37, 99, 235, 0.18);

  --font-display: 'Space Grotesk', 'Inter', sans-serif;
  --font-body: 'Inter', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  color: var(--c-text-main);
  background:
    radial-gradient(circle at 15% 8%, rgba(56, 189, 248, 0.14), transparent 42%),
    radial-gradient(circle at 85% 92%, rgba(37, 99, 235, 0.12), transparent 45%),
    linear-gradient(180deg, #F3F8FF 0%, #EAF1FC 45%, #E7EEFB 100%);
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
}

/* ---------- Background decorations ---------- */
.bg-decor {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
}
.bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(37, 99, 235, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37, 99, 235, 0.05) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(circle at 50% 0%, black 0%, transparent 70%);
}
.bg-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.55;
}
.bg-glow-1 {
  width: 480px; height: 480px;
  top: -140px; left: -120px;
  background: radial-gradient(circle, rgba(56,189,248,0.35), transparent 70%);
}
.bg-glow-2 {
  width: 560px; height: 560px;
  bottom: -220px; right: -160px;
  background: radial-gradient(circle, rgba(37,99,235,0.28), transparent 70%);
}

/* ---------- Typography helpers ---------- */
h1, h2, h3, h4, h5, .font-display {
  font-family: var(--font-display);
  letter-spacing: -0.01em;
  color: var(--c-secondary);
}
.text-gradient {
  background: linear-gradient(120deg, var(--c-primary) 0%, var(--c-accent) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.mono { font-family: var(--font-mono); }

/* ---------- Navbar ---------- */
.saes-navbar {
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: blur(16px) saturate(160%);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  border-bottom: 1px solid rgba(15, 23, 42, 0.06);
  padding: 0.85rem 0;
  transition: box-shadow 0.3s ease;
}
.saes-navbar.scrolled { box-shadow: var(--shadow-soft); }
.navbar-brand { display: flex; align-items: center; gap: 0.6rem; }
.brand-mark {
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; border-radius: 11px;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  color: #fff; font-size: 1.05rem;
  box-shadow: 0 6px 16px rgba(37,99,235,0.35);
}
.brand-text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--c-secondary);
}
.brand-accent { color: var(--c-primary); }
.saes-navbar .nav-link {
  font-weight: 500;
  color: var(--c-text-muted);
  padding: 0.5rem 0.9rem;
  border-radius: 10px;
  transition: all 0.2s ease;
}
.saes-navbar .nav-link:hover { color: var(--c-primary); background: rgba(37,99,235,0.08); }

/* ---------- Hero Section ---------- */
.hero-section { padding: 5.5rem 0 4rem; position: relative; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-size: 0.8rem; font-weight: 600; letter-spacing: 0.04em;
  color: var(--c-primary);
  background: rgba(37, 99, 235, 0.08);
  border: 1px solid rgba(37, 99, 235, 0.18);
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  margin-bottom: 1.25rem;
  text-transform: uppercase;
}
.hero-title {
  font-size: clamp(2.1rem, 4vw, 3rem);
  font-weight: 700;
  line-height: 1.12;
  margin-bottom: 0.6rem;
}
.hero-subtitle {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  color: var(--c-primary);
  font-weight: 500;
  margin-bottom: 1.1rem;
}
.hero-desc {
  color: var(--c-text-muted);
  font-size: 1.02rem;
  max-width: 560px;
  margin-bottom: 1.8rem;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 0.85rem; margin-bottom: 2.2rem; }

.btn-hero-primary {
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  color: #fff; font-weight: 600;
  padding: 0.75rem 1.6rem; border-radius: 14px;
  border: none;
  box-shadow: 0 10px 28px rgba(37,99,235,0.32);
  display: inline-flex; align-items: center; gap: 0.5rem;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.btn-hero-primary:hover { transform: translateY(-3px); box-shadow: 0 16px 34px rgba(37,99,235,0.4); color: #fff; }

.btn-hero-ghost {
  background: rgba(255,255,255,0.6);
  border: 1px solid rgba(15,23,42,0.12);
  color: var(--c-secondary); font-weight: 600;
  padding: 0.75rem 1.6rem; border-radius: 14px;
  display: inline-flex; align-items: center; gap: 0.5rem;
  transition: all 0.25s ease;
  backdrop-filter: blur(8px);
}
.btn-hero-ghost:hover { background: #fff; transform: translateY(-3px); color: var(--c-secondary); box-shadow: var(--shadow-soft); }

.hero-stats { display: flex; gap: 2.2rem; flex-wrap: wrap; }
.hero-stat { display: flex; flex-direction: column; }
.stat-num { font-family: var(--font-display); font-size: 1.5rem; font-weight: 700; color: var(--c-secondary); }
.stat-label { font-size: 0.78rem; color: var(--c-text-muted); text-transform: uppercase; letter-spacing: 0.04em; }

.hero-illustration { display: flex; justify-content: center; align-items: center; }
.hero-svg { width: 100%; max-width: 460px; height: auto; filter: drop-shadow(0 20px 40px rgba(37,99,235,0.25)); }
.shield-shape { animation: float-shield 5s ease-in-out infinite; transform-origin: center; }
.rotate-ring { animation: spin-ring 22s linear infinite; transform-origin: 260px 230px; }
.bin-particle {
  font-family: var(--font-mono); font-size: 13px; fill: var(--c-primary);
  opacity: 0.55; animation: pulse-particle 3.4s ease-in-out infinite;
}
.circuit-lines { animation: pulse-particle 4s ease-in-out infinite; }

@keyframes float-shield {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}
@keyframes spin-ring {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}
@keyframes pulse-particle {
  0%, 100% { opacity: 0.35; }
  50% { opacity: 0.8; }
}

/* ---------- Sections ---------- */
.section { padding: 4.5rem 0; }
.section-alt {
  background: linear-gradient(180deg, rgba(37,99,235,0.03), rgba(56,189,248,0.05));
  border-top: 1px solid rgba(15,23,42,0.04);
  border-bottom: 1px solid rgba(15,23,42,0.04);
}
.section-heading { max-width: 640px; margin-bottom: 2.4rem; }
.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem; font-weight: 600; letter-spacing: 0.06em;
  color: var(--c-accent); text-transform: uppercase;
}
.section-heading h2 { font-size: clamp(1.6rem, 2.6vw, 2.1rem); margin: 0.4rem 0 0.6rem; }
.section-heading p { color: var(--c-text-muted); margin: 0; }

/* ---------- Glass Cards ---------- */
.glass-card {
  position: relative;
  background: var(--c-glass-bg);
  border: 1px solid var(--c-glass-border);
  border-radius: var(--radius-card);
  padding: 2rem;
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  box-shadow: var(--shadow-soft);
  overflow: hidden;
}
.floating-card { transition: transform 0.35s ease, box-shadow 0.35s ease; }
.floating-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-strong); }
.card-glow {
  position: absolute; top: -60px; right: -60px;
  width: 200px; height: 200px; border-radius: 50%;
  background: radial-gradient(circle, rgba(37,99,235,0.16), transparent 70%);
  pointer-events: none;
}
.card-glow-accent { background: radial-gradient(circle, rgba(56,189,248,0.2), transparent 70%); }

.ref-card { height: 100%; }
.ref-card h5 { display: flex; align-items: center; gap: 0.55rem; font-size: 1.05rem; margin-bottom: 0.3rem; }
.ref-card h5 i { color: var(--c-primary); }
.ref-desc { color: var(--c-text-muted); font-size: 0.88rem; margin-bottom: 1.1rem; }

/* ---------- Mode tabs ---------- */
.saes-mode-tabs { background: rgba(15,23,42,0.05); padding: 0.3rem; border-radius: 14px; }
.saes-mode-tabs .nav-link {
  border-radius: 10px; color: var(--c-text-muted); font-weight: 600;
  padding: 0.55rem 0.8rem; transition: all 0.2s ease; border: none;
  display: flex; align-items: center; justify-content: center; gap: 0.4rem;
}
.saes-mode-tabs .nav-link.active {
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  color: #fff; box-shadow: 0 6px 16px rgba(37,99,235,0.3);
}

/* ---------- Form controls ---------- */
.form-label { font-weight: 600; font-size: 0.9rem; color: var(--c-secondary); margin-bottom: 0.5rem; }
.input-group-saes .input-group-text {
  background: rgba(255,255,255,0.7); border: 1px solid rgba(15,23,42,0.1);
  color: var(--c-primary);
}
.bit-input {
  font-family: var(--font-mono);
  letter-spacing: 0.12em;
  border: 1px solid rgba(15,23,42,0.1);
  background: rgba(255,255,255,0.75);
}
.bit-input:focus {
  box-shadow: 0 0 0 3px rgba(37,99,235,0.15);
  border-color: var(--c-primary);
}
.bit-input.is-valid { border-color: var(--c-success); }
.bit-input.is-invalid { border-color: var(--c-danger); }
.bit-counter { font-family: var(--font-mono); font-size: 0.78rem; min-width: 52px; text-align: center; }
.invalid-feedback-box {
  display: none;
  margin-top: 0.5rem;
  padding: 0.55rem 0.9rem;
  background: rgba(239, 68, 68, 0.08);
  border: 1px solid rgba(239, 68, 68, 0.25);
  color: #B91C1C;
  border-radius: 10px;
  font-size: 0.84rem;
}
.invalid-feedback-box.show { display: flex; align-items: center; gap: 0.5rem; }

/* ---------- Buttons ---------- */
.btn-saes-primary {
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  color: #fff; font-weight: 600; border: none;
  padding: 0.7rem 1.2rem; border-radius: 12px;
  display: flex; align-items: center; justify-content: center; gap: 0.5rem;
  transition: all 0.25s ease;
}
.btn-saes-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 26px rgba(37,99,235,0.32); color: #fff; }
.btn-saes-primary:disabled { opacity: 0.6; transform: none; box-shadow: none; }

.btn-saes-ghost {
  background: rgba(255,255,255,0.65);
  border: 1px solid rgba(15,23,42,0.12);
  color: var(--c-secondary); font-weight: 600;
  padding: 0.7rem 1.1rem; border-radius: 12px;
  transition: all 0.2s ease;
}
.btn-saes-ghost:hover { background: #fff; color: var(--c-secondary); box-shadow: var(--shadow-soft); }

.btn-copy {
  background: transparent; border: none; color: var(--c-primary);
  padding: 0.35rem 0.5rem; border-radius: 8px; transition: all 0.2s ease;
}
.btn-copy:hover { background: rgba(37,99,235,0.1); }
.btn-copy.copied { color: var(--c-success); }

/* ---------- Output ---------- */
.output-placeholder {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  text-align: center; color: var(--c-text-muted); padding: 3rem 1rem; gap: 0.75rem;
  min-height: 260px;
}
.output-placeholder i { font-size: 2.4rem; color: var(--c-accent); opacity: 0.7; }

.result-box { display: flex; flex-direction: column; gap: 0.6rem; }
.result-row {
  display: flex; align-items: center; gap: 0.7rem;
  background: rgba(255,255,255,0.7);
  border: 1px solid rgba(15,23,42,0.08);
  border-radius: 12px; padding: 0.65rem 0.9rem;
}
.result-tag {
  font-family: var(--font-mono); font-size: 0.72rem; font-weight: 700;
  color: var(--c-primary); background: rgba(37,99,235,0.1);
  padding: 0.2rem 0.5rem; border-radius: 6px; letter-spacing: 0.05em;
}
.result-value { font-size: 1.05rem; font-weight: 600; letter-spacing: 0.08em; flex: 1; word-break: break-all; }

/* ---------- State Matrix Visualization ---------- */
.state-matrix-wrapper { display: flex; gap: 2rem; flex-wrap: wrap; align-items: center; }
.state-matrix {
  display: grid; grid-template-columns: repeat(2, 56px); grid-template-rows: repeat(2, 56px);
  gap: 8px;
}
.state-matrix.small { grid-template-columns: repeat(2, 44px); grid-template-rows: repeat(2, 44px); }
.nibble-cell {
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono); font-weight: 700; font-size: 1.15rem;
  border-radius: 12px; color: #fff;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  box-shadow: 0 6px 14px rgba(37,99,235,0.28);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  cursor: default;
}
.nibble-cell:hover { transform: translateY(-3px) scale(1.05); box-shadow: 0 10px 20px rgba(37,99,235,0.4); }
.nibble-cell.key-cell { background: linear-gradient(135deg, var(--c-secondary), #334155); }
.nibble-cell.diff { background: linear-gradient(135deg, var(--c-warning), #FBBF24); }
.matrix-label { font-size: 0.78rem; color: var(--c-text-muted); text-align: center; margin-top: 0.5rem; font-weight: 600; }
.matrix-block { display: flex; flex-direction: column; align-items: center; }
.matrix-arrow { font-size: 1.4rem; color: var(--c-accent); }

/* ---------- Reference Tables ---------- */
.ref-table { width: 100%; border-collapse: collapse; font-family: var(--font-mono); text-align: center; }
.ref-table th, .ref-table td {
  padding: 0.55rem 0.4rem; border: 1px solid rgba(15,23,42,0.08);
  font-size: 0.92rem;
}
.ref-table th { background: rgba(37,99,235,0.08); color: var(--c-primary); font-weight: 700; }
.ref-table td { background: rgba(255,255,255,0.55); font-weight: 600; }
.ref-table td:hover { background: rgba(56,189,248,0.15); }

.const-matrix { display: flex; gap: 0.6rem; }
.const-matrix .matcol { display: flex; flex-direction: column; gap: 0.6rem; }
.const-matrix .matcell {
  width: 56px; height: 56px; display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono); font-weight: 700; font-size: 1.2rem; color: #fff;
  background: linear-gradient(135deg, var(--c-secondary), #1E293B);
  border-radius: 12px;
}
.rcon-display { display: flex; flex-direction: column; gap: 0.5rem; }
.rcon-display .rcon-row { display: flex; gap: 0.6rem; align-items: center; font-family: var(--font-mono); }
.rcon-display .rcon-tag {
  font-size: 0.72rem; font-weight: 700; color: var(--c-primary);
  background: rgba(37,99,235,0.1); padding: 0.2rem 0.5rem; border-radius: 6px;
}

/* ---------- Timeline (process steps) ---------- */
.process-timeline { display: flex; flex-direction: column; gap: 0.6rem; }
.timeline-step {
  display: flex; align-items: center; gap: 0.7rem;
  padding: 0.5rem 0.7rem; border-radius: 10px;
  background: rgba(255,255,255,0.5);
  font-size: 0.85rem; font-weight: 600; color: var(--c-text-muted);
}
.timeline-step.done { color: var(--c-success); background: rgba(16,185,129,0.08); }
.timeline-step .step-icon {
  width: 22px; height: 22px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  background: rgba(15,23,42,0.1); color: var(--c-text-muted); font-size: 0.7rem;
}
.timeline-step.done .step-icon { background: var(--c-success); color: #fff; }

/* ---------- Accordion (process detail) ---------- */
.saes-accordion .accordion-item {
  background: rgba(255,255,255,0.55);
  border: 1px solid rgba(15,23,42,0.07);
  border-radius: 14px !important;
  margin-bottom: 0.8rem;
  overflow: hidden;
}
.saes-accordion .accordion-button {
  background: transparent; font-weight: 600; color: var(--c-secondary);
  font-family: var(--font-display);
}
.saes-accordion .accordion-button:not(.collapsed) {
  background: linear-gradient(135deg, rgba(37,99,235,0.1), rgba(56,189,248,0.08));
  color: var(--c-primary); box-shadow: none;
}
.saes-accordion .accordion-button:focus { box-shadow: none; }
.saes-accordion .accordion-button::after { filter: hue-rotate(0deg); }
.accordion-body-inner { padding: 0.5rem 0.2rem; }

.step-block { margin-bottom: 1.4rem; }
.step-block:last-child { margin-bottom: 0; }
.step-block-title {
  font-family: var(--font-display); font-weight: 700; font-size: 0.95rem;
  color: var(--c-secondary); margin-bottom: 0.7rem; display: flex; align-items: center; gap: 0.5rem;
}
.step-block-title i { color: var(--c-accent); }

.gf-trace {
  background: rgba(15,23,42,0.04); border-radius: 12px; padding: 0.9rem 1rem;
  font-family: var(--font-mono); font-size: 0.82rem; line-height: 1.8;
}
.gf-trace .gf-line { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.gf-trace .gf-tag { color: var(--c-primary); font-weight: 700; min-width: 70px; }

.detail-table { width: 100%; font-family: var(--font-mono); font-size: 0.85rem; }
.detail-table th { color: var(--c-text-muted); font-weight: 600; padding: 0.35rem 0.5rem; text-align: left; }
.detail-table td { padding: 0.35rem 0.5rem; border-top: 1px solid rgba(15,23,42,0.06); }

.badge-word {
  display: inline-flex; align-items: center; gap: 0.35rem;
  font-family: var(--font-mono); font-weight: 700; font-size: 0.85rem;
  background: rgba(37,99,235,0.1); color: var(--c-primary);
  padding: 0.3rem 0.6rem; border-radius: 8px;
}

.mix-col-card {
  background: rgba(255,255,255,0.6); border: 1px solid rgba(15,23,42,0.06);
  border-radius: 14px; padding: 1rem; margin-bottom: 1rem;
}
.mix-term {
  background: rgba(15,23,42,0.03); border-radius: 10px; padding: 0.6rem 0.8rem;
  margin-bottom: 0.5rem; font-family: var(--font-mono); font-size: 0.82rem;
}

/* ---------- Footer ---------- */
.saes-footer {
  background: var(--c-secondary); color: rgba(255,255,255,0.75);
  padding: 3rem 0 1.5rem; margin-top: 2rem;
}
.footer-brand { display: flex; align-items: center; gap: 0.6rem; margin-bottom: 0.8rem; }
.footer-brand .brand-text { color: #fff; }
.footer-desc { color: rgba(255,255,255,0.6); max-width: 420px; font-size: 0.92rem; }
.footer-note { font-size: 0.88rem; color: rgba(255,255,255,0.65); }
.footer-divider { border-color: rgba(255,255,255,0.12); margin: 1.5rem 0 1rem; }
.footer-copy { font-size: 0.8rem; color: rgba(255,255,255,0.45); margin: 0; }

/* ---------- Empty states ---------- */
.empty-state {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  text-align: center; color: var(--c-text-muted); padding: 2.5rem 1rem; gap: 0.75rem;
}
.empty-state i { font-size: 2.2rem; color: var(--c-accent); opacity: 0.6; }

/* ---------- Fade-in animation utility ---------- */
.fade-in-up { animation: fadeInUp 0.5s ease both; }
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Toast */
.toast { background: rgba(255,255,255,0.9); backdrop-filter: blur(10px); border: 1px solid rgba(15,23,42,0.08); }