/* ═══════════════════════════════════════════════════
   IEEE SPS — SIGNAL PROCESSING SUMMIT
   Theme: Deep-Space Sci-Fi / Signal-wave aesthetic
   Fonts: Orbitron (display) · IBM Plex Mono (labels) · Outfit (body)
   ═══════════════════════════════════════════════════ */

/* ── CSS VARIABLES ────────────────────────────────── */
:root {
  --bg:          #04080f;
  --surface:     #080d18;
  --surface-2:   #0d1526;
  --surface-3:   #121d35;
  --border:      rgba(0, 245, 255, 0.12);
  --border-mid:  rgba(0, 245, 255, 0.25);
  --border-hi:   rgba(0, 245, 255, 0.55);

  --cyan:        #00f5ff;
  --cyan-dim:    rgba(0, 245, 255, 0.12);
  --cyan-glow:   rgba(0, 245, 255, 0.35);
  --violet:      #7b2fff;
  --violet-dim:  rgba(123, 47, 255, 0.18);
  --violet-glow: rgba(123, 47, 255, 0.45);
  --text:        #dce8ff;
  --text-dim:    #7a93c0;
  --text-muted:  #3a5070;

  --radius-sm: 6px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-xl: 32px;

  --font-display: 'Orbitron', sans-serif;
  --font-mono:    'IBM Plex Mono', monospace;
  --font-body:    'Outfit', sans-serif;

  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── RESET & BASE ─────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── CANVAS / OVERLAYS ────────────────────────────── */
#bgCanvas {
  position: fixed; inset: 0; z-index: 0;
  pointer-events: none; opacity: 0.6;
}
.noise-overlay {
  position: fixed; inset: 0; z-index: 1; pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='1'/%3E%3C/svg%3E");
  opacity: 0.025;
}
.scanlines {
  position: fixed; inset: 0; z-index: 1; pointer-events: none;
  background: repeating-linear-gradient(to bottom, transparent 0px, transparent 2px, rgba(0,0,0,0.08) 2px, rgba(0,0,0,0.08) 4px);
}

/* ════════════════════════════════════════════════════
   TWO-PAGE SLIDE SYSTEM
   ════════════════════════════════════════════════════ */
.app-shell {
  position: relative;
  z-index: 10;
  overflow: hidden;
}

.slide {
  width: 100%;
  opacity: 1;
  transform: translateX(0);
  transition: opacity 0.5s ease, transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Hidden state — pushed off to the right */
.slide--hidden {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  opacity: 0;
  transform: translateX(40px);
  pointer-events: none;
}

/* Exiting state — pushed off to the left */
.slide--exit {
  opacity: 0;
  transform: translateX(-40px);
  pointer-events: none;
}

/* Entering state — fades in from right */
.slide--enter {
  opacity: 1;
  transform: translateX(0);
  pointer-events: auto;
}

/* ── PAGE WRAPPER ─────────────────────────────────── */
.page-wrapper {
  max-width: 760px;
  margin: 0 auto;
  padding: 40px 20px 60px;
}
.page-wrapper--form {
  max-width: 700px;
}

/* ════════════════════════════════════════════════════
   HERO — PAGE 1
   ════════════════════════════════════════════════════ */
.hero { text-align: center; padding: 20px 0 10px; animation: fadeUp 0.9s ease both; }

.hero-top {
  display: flex; align-items: center; justify-content: center;
  gap: 14px; margin-bottom: 36px;
}

.ieee-badge {
  display: flex; align-items: baseline; gap: 5px;
  border: 1.5px solid var(--border-mid);
  border-radius: var(--radius-sm);
  padding: 5px 12px;
  background: rgba(0, 245, 255, 0.04);
  backdrop-filter: blur(8px);
}
.ieee-badge--sm { padding: 4px 10px; }

.ieee-text {
  font-family: var(--font-display); font-size: 15px;
  font-weight: 800; letter-spacing: 0.12em; color: var(--cyan);
}
.sps-text {
  font-family: var(--font-mono); font-size: 11px;
  font-weight: 500; color: var(--violet); letter-spacing: 0.15em;
}
.chapter-label {
  font-family: var(--font-mono); font-size: 11px;
  color: var(--text-dim); letter-spacing: 0.15em; text-transform: uppercase;
}

/* ── LOGO ─────────────────────────────────────────── */
.logo-wrap {
  position: relative; width: 130px; height: 130px;
  margin: 0 auto 32px;
  display: flex; align-items: center; justify-content: center;
}
.logo-ring {
  position: absolute; border-radius: 50%;
  border: 1.5px solid var(--border);
  animation: spin linear infinite;
}
.logo-ring-outer { width: 130px; height: 130px; border-top-color: var(--cyan); border-right-color: transparent; animation-duration: 8s; }
.logo-ring-mid   { width: 108px; height: 108px; border-bottom-color: var(--violet); border-left-color: transparent; animation-duration: 5s; animation-direction: reverse; }

.logo-placeholder {
  width: 88px; height: 88px; border-radius: 50%;
  background: var(--surface-2); border: 1.5px solid var(--border-mid);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; overflow: hidden; transition: var(--transition);
}
.logo-placeholder:hover { border-color: var(--cyan); box-shadow: 0 0 20px var(--cyan-glow); }
.logo-inner { display: flex; flex-direction: column; align-items: center; gap: 4px; }
.logo-icon  { width: 42px; height: 42px; }
.logo-label { font-family: var(--font-mono); font-size: 7px; letter-spacing: 0.15em; color: var(--text-muted); text-transform: uppercase; }

/* ── TITLE ────────────────────────────────────────── */
.event-title-block { margin-bottom: 28px; }
.event-eyebrow {
  font-family: var(--font-mono); font-size: 11px;
  letter-spacing: 0.25em; color: var(--cyan);
  text-transform: uppercase; margin-bottom: 10px; opacity: 0.8;
}
.event-title {
  font-family: var(--font-display);
  font-size: clamp(42px, 9vw, 72px);
  font-weight: 900; letter-spacing: -0.01em; line-height: 1; color: white;
  text-shadow: 0 0 40px rgba(0,245,255,0.25); margin-bottom: 16px;
}
.title-accent {
  color: var(--cyan);
  text-shadow: 0 0 30px var(--cyan-glow), 0 0 60px rgba(0,245,255,0.2);
}
.event-subtitle {
  font-size: 15px; color: var(--text-dim);
  line-height: 1.7; max-width: 400px; margin: 0 auto;
}

/* ── META STRIP ───────────────────────────────────── */
.event-meta {
  display: flex; align-items: center; justify-content: center;
  flex-wrap: wrap; margin: 28px auto 0;
  background: var(--surface-2); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 14px 28px;
  width: fit-content; max-width: 100%;
  backdrop-filter: blur(12px);
}
.meta-item { display: flex; align-items: center; gap: 8px; padding: 0 18px; }
.meta-icon-svg { width: 14px; height: 14px; color: var(--cyan); stroke: currentColor; flex-shrink: 0; }
.meta-text { font-family: var(--font-mono); font-size: 12px; color: var(--text-dim); letter-spacing: 0.05em; }
.meta-divider { width: 1px; height: 20px; background: var(--border); }

/* ════════════════════════════════════════════════════
   ABOUT SECTION
   ════════════════════════════════════════════════════ */
.about-section { margin: 48px 0 40px; animation: fadeUp 0.9s 0.15s ease both; }

.about-card {
  background: linear-gradient(135deg, var(--surface-2) 0%, var(--surface-3) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 36px;
  position: relative; overflow: hidden;
}
.about-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, transparent, var(--cyan), var(--violet), transparent);
}
.about-card::after {
  content: ''; position: absolute;
  bottom: -60px; right: -60px;
  width: 200px; height: 200px;
  background: radial-gradient(circle, var(--violet-dim) 0%, transparent 70%);
  pointer-events: none;
}

.about-tag {
  display: inline-flex; align-items: center;
  font-family: var(--font-mono); font-size: 10px;
  letter-spacing: 0.2em; text-transform: uppercase;
  color: var(--cyan); border: 1px solid var(--cyan-dim);
  border-radius: 100px; padding: 4px 12px;
  margin-bottom: 16px; background: var(--cyan-dim);
}
.about-text {
  font-size: 15px; color: var(--text-dim);
  line-height: 1.75; margin-bottom: 24px; position: relative; z-index: 1;
}

/* ── HIGHLIGHT CHIPS WITH LUCIDE ICONS ────────────── */
.about-highlights { display: flex; flex-wrap: wrap; gap: 10px; }

.highlight-chip {
  display: inline-flex; align-items: center; gap: 9px;
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.05em;
  color: var(--text);
  padding: 9px 16px 9px 10px;
  border-radius: var(--radius-md);
  background: var(--surface-3);
  border: 1px solid var(--border-mid);
  transition: var(--transition);
  cursor: default;
  position: relative; overflow: hidden;
}
.highlight-chip::before {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(135deg, var(--cyan-dim), var(--violet-dim));
  opacity: 0; transition: opacity 0.3s;
}
.highlight-chip:hover { border-color: var(--cyan); color: var(--cyan); }
.highlight-chip:hover::before { opacity: 1; }
.highlight-chip:hover .chip-icon-wrap { background: rgba(0,245,255,0.2); }

.chip-icon-wrap {
  display: flex; align-items: center; justify-content: center;
  width: 26px; height: 26px; border-radius: 7px;
  background: var(--surface-2); border: 1px solid var(--border);
  flex-shrink: 0; transition: var(--transition);
  position: relative; z-index: 1;
}
.chip-icon {
  width: 13px; height: 13px;
  color: var(--cyan); stroke: currentColor;
}
.highlight-chip span:last-child { position: relative; z-index: 1; }

/* ════════════════════════════════════════════════════
   NAV ROW — NEXT BUTTON (PAGE 1 BOTTOM)
   ════════════════════════════════════════════════════ */
.nav-row {
  display: flex; flex-direction: column; align-items: center; gap: 12px;
  margin-top: 8px;
  animation: fadeUp 0.9s 0.3s ease both;
}

.next-btn {
  display: inline-flex; align-items: center; gap: 0;
  background: transparent;
  border: 1.5px solid var(--border-mid);
  border-radius: var(--radius-md);
  color: var(--text); cursor: pointer;
  font-family: var(--font-display); font-size: 13px;
  font-weight: 700; letter-spacing: 0.18em;
  overflow: hidden; position: relative;
  transition: all 0.35s ease;
  padding: 0;
}
.next-btn .btn-text {
  padding: 15px 24px;
  position: relative; z-index: 1; transition: color 0.3s;
}
.next-btn .btn-icon-wrap {
  display: flex; align-items: center; justify-content: center;
  width: 52px; height: 100%;
  background: var(--violet); border-left: 1px solid var(--violet);
  padding: 15px 0;
  position: relative; z-index: 1;
  transition: background 0.3s, width 0.3s;
  flex-shrink: 0;
}
.btn-nav-icon { width: 16px; height: 16px; stroke: white; transition: transform 0.3s; }
.next-btn:hover { border-color: var(--cyan); box-shadow: 0 0 24px var(--cyan-glow); }
.next-btn:hover .btn-text { color: var(--cyan); }
.next-btn:hover .btn-icon-wrap { background: var(--cyan); width: 60px; }
.next-btn:hover .btn-nav-icon { transform: translateX(3px); }

.btn-shine {
  position: absolute; top: 0; left: -100%; width: 60%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.08), transparent);
  animation: shine 3s ease-in-out infinite;
}

.nav-hint {
  font-family: var(--font-mono); font-size: 11px;
  color: var(--text-muted); letter-spacing: 0.1em;
}

/* ════════════════════════════════════════════════════
   BACK ROW — PAGE 2 TOP
   ════════════════════════════════════════════════════ */
.back-row {
  display: flex; align-items: center;
  justify-content: space-between;
  margin-bottom: 28px;
  animation: fadeUp 0.6s ease both;
}

.back-btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: transparent; border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-dim); cursor: pointer;
  font-family: var(--font-mono); font-size: 12px;
  letter-spacing: 0.08em;
  padding: 9px 16px;
  transition: var(--transition);
}
.back-btn:hover { border-color: var(--cyan); color: var(--cyan); }
.back-btn:hover .btn-nav-icon { transform: translateX(-3px); }

/* ════════════════════════════════════════════════════
   REGISTRATION FORM — PAGE 2
   ════════════════════════════════════════════════════ */
.form-section { animation: fadeUp 0.7s 0.1s ease both; }

.form-card {
  background: linear-gradient(160deg, var(--surface-2) 0%, var(--surface) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 40px 40px 36px;
  position: relative; overflow: hidden;
  box-shadow: 0 0 0 1px rgba(0,245,255,0.04),
              0 40px 80px rgba(0,0,0,0.6),
              inset 0 1px 0 rgba(255,255,255,0.04);
}
.form-card::before {
  content: ''; position: absolute; top: 0; left: 50%; transform: translateX(-50%);
  width: 80%; height: 1px;
  background: linear-gradient(90deg, transparent, var(--cyan), transparent);
}
.form-card::after {
  content: ''; position: absolute; top: -80px; right: -80px;
  width: 220px; height: 220px;
  background: radial-gradient(circle, rgba(123,47,255,0.12) 0%, transparent 70%);
  pointer-events: none;
}

/* ── FORM HEADER ──────────────────────────────────── */
.form-card-header { text-align: center; margin-bottom: 32px; }

.form-card-title {
  display: flex; align-items: center; justify-content: center;
  gap: 16px; margin-bottom: 10px;
}
.form-card-title h2 {
  font-family: var(--font-display); font-size: 20px;
  font-weight: 700; letter-spacing: 0.1em;
  text-transform: uppercase; color: white;
  white-space: nowrap;
}
.form-title-line {
  flex: 1; height: 1px; max-width: 60px;
  background: linear-gradient(90deg, transparent, var(--border-mid));
}
.form-title-line:last-child { background: linear-gradient(90deg, var(--border-mid), transparent); }

.form-card-sub {
  font-family: var(--font-mono); font-size: 12px;
  color: var(--text-muted); letter-spacing: 0.05em; margin-bottom: 16px;
}

/* ── SEATS INDICATOR ──────────────────────────────── */
.seats-indicator { display: flex; align-items: center; gap: 10px; justify-content: center; }
.seats-bar {
  width: 100px; height: 4px;
  background: var(--surface-3); border-radius: 100px; overflow: hidden;
}
.seats-fill {
  height: 100%; width: 68%;
  background: linear-gradient(90deg, var(--violet), var(--cyan));
  border-radius: 100px; animation: pulse-bar 2s ease-in-out infinite;
}
.seats-text { font-family: var(--font-mono); font-size: 10px; color: var(--cyan); letter-spacing: 0.1em; }

/* ── FORM FIELDS ──────────────────────────────────── */
.field-group { margin-bottom: 20px; }

/* Two-column layout for email + phone */
.field-row {
  display: grid; grid-template-columns: 1fr 1fr; gap: 16px;
}

.field-label {
  display: block; font-family: var(--font-mono);
  font-size: 11px; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--text-dim); margin-bottom: 8px;
}

.input-wrap { position: relative; }

.input-icon {
  position: absolute; left: 14px; top: 50%; transform: translateY(-50%);
  width: 15px; height: 15px; color: var(--text-muted);
  stroke: currentColor; pointer-events: none;
  transition: color 0.3s;
}

.input-wrap input {
  width: 100%;
  background: var(--surface-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text);
  font-family: var(--font-body); font-size: 15px;
  padding: 13px 16px 13px 42px;
  outline: none;
  transition: var(--transition);
  -webkit-appearance: none;
}
.input-wrap input::placeholder { color: var(--text-muted); font-size: 14px; }
.input-wrap input:focus {
  border-color: var(--cyan);
  background: rgba(13,21,38,0.9);
  box-shadow: 0 0 0 3px rgba(0,245,255,0.1);
}
.input-wrap input:focus ~ .input-glow { opacity: 0.3; }
.input-wrap input:focus + .input-icon,
.input-wrap:focus-within .input-icon { color: var(--cyan); }

.input-glow {
  position: absolute; inset: -1px; border-radius: var(--radius-md);
  pointer-events: none; opacity: 0;
  background: linear-gradient(135deg, var(--cyan-glow), var(--violet-glow));
  filter: blur(8px); transition: opacity 0.3s; z-index: -1;
}

/* ── SUBMIT BUTTON ────────────────────────────────── */
.submit-btn {
  width: 100%; padding: 16px 24px; margin-top: 8px;
  background: linear-gradient(135deg, var(--violet) 0%, #5b1fd4 50%, #0090ff 100%);
  background-size: 200% 200%; background-position: 0% 50%;
  border: none; border-radius: var(--radius-md);
  color: white; cursor: pointer;
  font-family: var(--font-display); font-size: 13px;
  font-weight: 700; letter-spacing: 0.18em;
  position: relative; overflow: hidden;
  transition: all 0.4s ease;
  display: flex; align-items: center; justify-content: center; gap: 12px;
}
.submit-btn:hover {
  background-position: 100% 50%;
  box-shadow: 0 0 30px var(--violet-glow), 0 0 60px rgba(0,245,255,0.15);
  transform: translateY(-2px);
}
.submit-btn:active { transform: translateY(0); }
.submit-btn:disabled { opacity: 0.6; cursor: not-allowed; transform: none; }

.btn-submit-icon { width: 16px; height: 16px; stroke: white; flex-shrink: 0; }

/* ── FORM MESSAGE ─────────────────────────────────── */
.form-message {
  margin-top: 18px; min-height: 24px;
  text-align: center; font-family: var(--font-mono);
  font-size: 13px; letter-spacing: 0.05em;
  border-radius: var(--radius-md); padding: 0;
  transition: var(--transition);
}
.form-message.success {
  color: var(--cyan); background: rgba(0,245,255,0.07);
  border: 1px solid rgba(0,245,255,0.2); padding: 14px 20px;
}
.form-message.error {
  color: #ff6b6b; background: rgba(255,107,107,0.07);
  border: 1px solid rgba(255,107,107,0.2); padding: 14px 20px;
}

/* ════════════════════════════════════════════════════
   FOOTER
   ════════════════════════════════════════════════════ */
.site-footer {
  text-align: center; margin-top: 48px;
  font-family: var(--font-mono); font-size: 11px;
  color: var(--text-muted); letter-spacing: 0.1em;
}

/* ════════════════════════════════════════════════════
   ANIMATIONS
   ════════════════════════════════════════════════════ */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}
@keyframes shine {
  0%   { left: -100%; }
  40%  { left: 120%; }
  100% { left: 120%; }
}
@keyframes pulse-bar {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.6; }
}

/* ════════════════════════════════════════════════════
   RESPONSIVE
   ════════════════════════════════════════════════════ */
@media (max-width: 600px) {
  .page-wrapper { padding: 24px 16px 48px; }
  .form-card { padding: 28px 20px 28px; border-radius: var(--radius-lg); }
  .about-card { padding: 24px 18px; }
  .field-row { grid-template-columns: 1fr; }
  .event-meta { padding: 12px 16px; }
  .meta-item { padding: 4px 10px; }
  .hero-top { flex-direction: column; gap: 8px; }
  .next-btn .btn-text { font-size: 11px; padding: 14px 18px; }
  .back-row { margin-bottom: 20px; }
}

@media (max-width: 380px) {
  .event-meta { flex-direction: column; gap: 8px; }
  .meta-divider { width: 40px; height: 1px; }
}

/* ── ACCESSIBILITY ─────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}
input:focus-visible, button:focus-visible {
  outline: 2px solid var(--cyan); outline-offset: 3px;
}

/* ── CUSTOM SELECT (YEAR DROPDOWN) ────────────────── */
.input-wrap select.custom-select {
  width: 100%;
  background: var(--surface-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 15px;
  padding: 13px 40px 13px 42px; /* Extra right padding for the arrow */
  outline: none;
  transition: var(--transition);
  -webkit-appearance: none;
  appearance: none;
  cursor: pointer;
  position: relative;
  z-index: 2;
}

.input-wrap select.custom-select:focus {
  border-color: var(--cyan);
  background: rgba(13,21,38,0.9);
  box-shadow: 0 0 0 3px rgba(0,245,255,0.1);
}

.input-wrap select.custom-select:focus ~ .input-glow { opacity: 0.3; }

.select-arrow {
  position: absolute;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  color: var(--text-muted);
  pointer-events: none; /* Lets clicks pass through to the select element */
  z-index: 3;
  transition: color 0.3s;
}

.input-wrap select.custom-select:focus ~ .select-arrow {
  color: var(--cyan);
}

/* Style the dropdown menu items for Dark Mode */
.input-wrap select.custom-select option {
  background-color: var(--surface-2);
  color: var(--text);
}