/* ========================================
   唐姝 · Login — Styles
   ======================================== */

/* ---------- Reset & Base ---------- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  height: 100%;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

html::-webkit-scrollbar {
  display: none;
}

body {
  height: 100%;
  font-family: 'Noto Serif SC', 'Source Han Serif SC', 'STSong', 'SimSun', 'Songti SC', serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background: #0a0a0a;
  color: #fff;
  overflow-x: hidden;
  overflow-y: auto;
}

/* ========================================
   Parallax Background (fixed)
   ======================================== */

#parallax-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  background:
    linear-gradient(rgba(0, 0, 0, 0.35), rgba(0, 0, 0, 0.35)),
    url('../images/assets/denki-bg-gy.webp') center / cover no-repeat;
}

#parallax-bg-lit {
  position: absolute;
  inset: 0;
  background: url('../images/assets/denki-bg.webp') center / cover no-repeat;
  opacity: 0;
  transition: opacity 0.8s ease;
  pointer-events: none;
}

#parallax-bg.lit #parallax-bg-lit {
  opacity: 1;
}

/* ========================================
   Top Navigation Bar
   ======================================== */

#top-nav {
  position: fixed;
  top: clamp(1.5rem, 4vh, 2.5rem);
  right: clamp(1rem, 3vw, 2rem);
  z-index: 15;
  display: flex;
  align-items: center;
}

.nav-items {
  display: flex;
  gap: 0.4rem;
}

.nav-item {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.92);
  color: #111;
  font-family: 'Helvetica Neue', 'Arial', 'Helvetica', sans-serif;
  font-size: clamp(0.65rem, 0.9vw, 0.8rem);
  font-weight: 800;
  letter-spacing: 0.13em;
  text-decoration: none;
  padding: 0.4rem 0.85rem;
  transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
  white-space: nowrap;
}

.nav-item:hover {
  background: #fff;
  transform: translateY(-1px);
}

/* LOGIN outline style */
.nav-item.nav-login {
  background: transparent;
  color: #C41E3A;
  border: 1px solid #C41E3A;
}

.nav-item.nav-login:hover {
  background: #C41E3A;
  color: #fff;
}

/* ========================================
   Logo (fixed, top-left)
   ======================================== */

#logo {
  position: fixed;
  top: 0.5rem;
  left: 1rem;
  width: clamp(120px, 14vw, 180px);
  height: auto;
  z-index: 10;
  opacity: 0.6;
  pointer-events: none;
}

/* ========================================
   Login Card — Centered on Screen
   ======================================== */

.login-wrapper {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: clamp(1rem, 3vw, 2rem);
}

.login-card {
  width: 100%;
  min-width: 320px;
  max-width: 420px;
  background: rgba(8, 8, 8, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 4px;
  padding: clamp(2rem, 5vh, 3rem) clamp(1.5rem, 4vw, 2.5rem);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

/* ---------- Card Header ---------- */
.login-header {
  text-align: center;
  margin-bottom: 2rem;
}

.login-title {
  font-size: clamp(1.8rem, 3.5vw, 2.4rem);
  font-weight: 400;
  letter-spacing: 0.25em;
  color: #C41E3A;
  margin-bottom: 0.3em;
}

.login-subtitle {
  font-family: 'Helvetica Neue', 'Arial', 'Helvetica', sans-serif;
  font-size: clamp(0.7rem, 0.9vw, 0.8rem);
  font-weight: 600;
  letter-spacing: 0.15em;
  color: rgba(255, 255, 255, 0.35);
  text-transform: uppercase;
}

/* ========================================
   Form Fields
   ======================================== */

.login-form {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

/* ---------- Input Group ---------- */
.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.input-label {
  font-family: 'Helvetica Neue', 'Arial', 'Helvetica', sans-serif;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: rgba(255, 255, 255, 0.45);
  text-transform: uppercase;
  padding-left: 0.1rem;
}

.input-field {
  background: rgba(255, 255, 255, 0.06);
  border: none;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  color: #fff;
  font-family: inherit;
  font-size: clamp(0.85rem, 1vw, 0.95rem);
  letter-spacing: 0.03em;
  padding: 0.6rem 0.2rem;
  outline: none;
  transition: border-color 0.3s ease, background 0.3s ease;
}

.input-field:focus {
  border-bottom-color: #C41E3A;
  background: rgba(255, 255, 255, 0.09);
}

.input-field::placeholder {
  color: rgba(255, 255, 255, 0.2);
}

/* ---------- Password Field with Toggle ---------- */
.password-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.password-wrapper .input-field {
  flex: 1;
  padding-right: 2.5rem;
}

.btn-toggle-password {
  position: absolute;
  right: 0.2rem;
  background: none;
  border: none;
  color: rgba(255, 255, 255, 0.35);
  cursor: pointer;
  padding: 0.4rem;
  font-size: 0.85rem;
  line-height: 1;
  transition: color 0.2s ease;
}

.btn-toggle-password:hover {
  color: rgba(255, 255, 255, 0.7);
}

/* ---------- Row: Remember + Forgot ---------- */
.form-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Checkbox */
.checkbox-group {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  cursor: pointer;
}

.checkbox-group input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: transparent;
  cursor: pointer;
  position: relative;
  flex-shrink: 0;
}

.checkbox-group input[type="checkbox"]:checked {
  background: #C41E3A;
  border-color: #C41E3A;
}

.checkbox-group input[type="checkbox"]:checked::after {
  content: '';
  position: absolute;
  left: 3px;
  top: 1px;
  width: 5px;
  height: 8px;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.checkbox-label {
  font-family: 'Helvetica Neue', 'Arial', 'Helvetica', sans-serif;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  color: rgba(255, 255, 255, 0.45);
  user-select: none;
}

/* Forgot password link */
.link-forgot {
  font-family: 'Helvetica Neue', 'Arial', 'Helvetica', sans-serif;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  color: rgba(255, 255, 255, 0.4);
  text-decoration: none;
  transition: color 0.2s ease;
}

.link-forgot:hover {
  color: #C41E3A;
}

/* ========================================
   Buttons
   ======================================== */

.btn-login {
  width: 100%;
  padding: 0.7rem;
  background: #C41E3A;
  border: none;
  color: #fff;
  font-family: 'Helvetica Neue', 'Arial', 'Helvetica', sans-serif;
  font-size: clamp(0.8rem, 0.95vw, 0.9rem);
  font-weight: 700;
  letter-spacing: 0.12em;
  cursor: pointer;
  transition: background 0.25s ease, transform 0.15s ease, opacity 0.25s ease;
}

.btn-login:hover {
  background: #a01830;
}

.btn-login:active {
  transform: scale(0.97);
}

.btn-login.loading {
  pointer-events: none;
  opacity: 0.7;
}

/* ========================================
   Register Link
   ======================================== */

.register-hint {
  text-align: center;
  margin-top: 1.5rem;
  font-family: 'Helvetica Neue', 'Arial', 'Helvetica', sans-serif;
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  color: rgba(255, 255, 255, 0.35);
}

.link-register {
  color: #C41E3A;
  text-decoration: none;
  font-weight: 700;
  margin-left: 0.3em;
  transition: color 0.2s ease;
}

.link-register:hover {
  color: #e05060;
}

/* ========================================
   Validation Error
   ======================================== */

.input-field.error {
  border-bottom-color: #E57373;
}

.error-message {
  font-family: 'Helvetica Neue', 'Arial', 'Helvetica', sans-serif;
  font-size: 0.65rem;
  font-weight: 500;
  color: #E57373;
  letter-spacing: 0.03em;
  padding-left: 0.1rem;
  display: none;
}

.error-message.visible {
  display: block;
}

/* ========================================
   Back to Top Button
   ======================================== */

#back-to-top {
  position: fixed;
  bottom: clamp(2rem, 5vh, 3.5rem);
  right: clamp(1.5rem, 4vw, 2.5rem);
  z-index: 20;
  width: clamp(44px, 5vw, 54px);
  height: clamp(44px, 5vw, 54px);
  background: #C41E3A;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  transform: translateX(120%);
  opacity: 0;
  transition: transform 0.5s cubic-bezier(0.16, 1, 0.3, 1),
              opacity 0.35s ease,
              background 0.25s ease;
}

#back-to-top.visible {
  transform: translateX(0);
  opacity: 1;
}

#back-to-top:hover {
  background: #a01830;
}

#back-to-top:active {
  transform: translateX(0) scale(0.95);
}

#back-to-top svg {
  display: block;
  pointer-events: none;
}

/* ========================================
   Toast Notification
   ======================================== */

.toast {
  position: fixed;
  top: clamp(1.5rem, 4vh, 2.5rem);
  left: 50%;
  transform: translateX(-50%) translateY(-120%);
  z-index: 300;
  background: #C41E3A;
  color: #fff;
  font-family: 'Helvetica Neue', 'Arial', 'Helvetica', sans-serif;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 0.7rem 1.5rem;
  border-radius: 2px;
  pointer-events: none;
  opacity: 0;
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
              opacity 0.3s ease;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* ========================================
   Responsive
   ======================================== */

@media (max-width: 768px) {
  .login-card {
    min-width: unset;
    max-width: 92vw;
    padding: 1.8rem 1.3rem;
  }

  #top-nav {
    top: clamp(1rem, 3vh, 1.8rem);
    right: clamp(0.5rem, 2vw, 1rem);
  }

  .nav-item {
    font-size: 0.6rem;
    letter-spacing: 0.08em;
    padding: 0.3rem 0.55rem;
  }
}

@media (max-width: 480px) {
  .login-card {
    max-width: 96vw;
  }

  .form-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.8rem;
  }

  .login-title {
    font-size: 1.5rem;
  }
}