/* ============================================
   NilaiTools — Design System & Styles
   ============================================ */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=JetBrains+Mono:wght@500;700&display=swap');

/* --- CSS Custom Properties --- */
:root {
  /* Colors */
  --color-primary: #2563EB;
  --color-primary-hover: #1D4ED8;
  --color-primary-light: #DBEAFE;
  --color-primary-50: #EFF6FF;
  --color-secondary: #7C3AED;
  --color-secondary-hover: #6D28D9;
  --color-secondary-light: #EDE9FE;
  --color-accent: #10B981;
  --color-accent-hover: #059669;
  --color-accent-light: #D1FAE5;

  /* Neutrals */
  --color-bg: #F1F5F9;
  --color-surface: #FFFFFF;
  --color-surface-alt: #F8FAFC;
  --color-border: #E2E8F0;
  --color-border-hover: #CBD5E1;
  --color-text: #1E293B;
  --color-text-secondary: #64748B;
  --color-text-muted: #94A3B8;

  /* Semantic */
  --color-error: #EF4444;
  --color-error-bg: #FEF2F2;
  --color-error-border: #FECACA;
  --color-warning: #F59E0B;
  --color-warning-bg: #FFFBEB;
  --color-success: #10B981;
  --color-success-bg: #ECFDF5;
  --color-info: #3B82F6;
  --color-info-bg: #EFF6FF;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #2563EB 0%, #7C3AED 100%);
  --gradient-hero: linear-gradient(135deg, #1E293B 0%, #0F172A 50%, #1E1B4B 100%);
  --gradient-card: linear-gradient(135deg, rgba(37, 99, 235, 0.05) 0%, rgba(124, 58, 237, 0.05) 100%);
  --gradient-result: linear-gradient(135deg, #2563EB 0%, #7C3AED 50%, #10B981 100%);
  --gradient-shine: linear-gradient(90deg, transparent, rgba(255,255,255,0.08), transparent);

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: 'JetBrains Mono', SFMono-Regular, Consolas, monospace;

  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-lg: 1.125rem;
  --fs-xl: 1.25rem;
  --fs-2xl: 1.5rem;
  --fs-3xl: 1.875rem;
  --fs-4xl: 2.25rem;
  --fs-5xl: 3rem;

  --fw-normal: 400;
  --fw-medium: 500;
  --fw-semibold: 600;
  --fw-bold: 700;
  --fw-extrabold: 800;

  --lh-tight: 1.25;
  --lh-normal: 1.5;
  --lh-relaxed: 1.75;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --shadow-glow: 0 0 20px rgba(37, 99, 235, 0.15);
  --shadow-glow-lg: 0 0 40px rgba(37, 99, 235, 0.2);

  /* Borders */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.25rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
  --transition-spring: 400ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Layout */
  --container-max: 1200px;
  --container-narrow: 800px;
  --navbar-height: 64px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--lh-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-hover);
}

ul, ol {
  list-style: none;
}

button {
  cursor: pointer;
  font-family: inherit;
  border: none;
  background: none;
}

input, select, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* --- Container --- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-5);
}

.container--narrow {
  max-width: var(--container-narrow);
}

/* ============================================
   Navbar
   ============================================ */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--color-border);
  height: var(--navbar-height);
  transition: box-shadow var(--transition-base);
}

.navbar.scrolled {
  box-shadow: var(--shadow-md);
}

.navbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.navbar__brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--fs-xl);
  font-weight: var(--fw-bold);
  color: var(--color-text);
  text-decoration: none;
}

.navbar__logo {
  height: 32px;
  width: auto;
  display: block;
  object-fit: contain;
}

.navbar__links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.navbar__link {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.navbar__link:hover,
.navbar__link--active {
  color: var(--color-primary);
  background: var(--color-primary-50);
}

.navbar__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--space-2);
  cursor: pointer;
}

.navbar__toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.navbar__toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.navbar__toggle.active span:nth-child(2) {
  opacity: 0;
}

.navbar__toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile nav */
@media (max-width: 768px) {
  .navbar__toggle {
    display: flex;
  }

  .navbar__links {
    position: fixed;
    top: var(--navbar-height);
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    flex-direction: column;
    padding: var(--space-4);
    gap: var(--space-1);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    transform: translateY(-110%);
    opacity: 0;
    transition: all var(--transition-base);
    pointer-events: none;
  }

  .navbar__links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .navbar__link {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: var(--fs-base);
  }
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  background: var(--gradient-hero);
  padding: var(--space-20) 0 var(--space-24);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 20% 50%, rgba(37, 99, 235, 0.15) 0%, transparent 50%),
              radial-gradient(ellipse at 80% 20%, rgba(124, 58, 237, 0.12) 0%, transparent 50%),
              radial-gradient(ellipse at 60% 80%, rgba(16, 185, 129, 0.08) 0%, transparent 50%);
  animation: heroGlow 8s ease-in-out infinite alternate;
}

@keyframes heroGlow {
  0% { opacity: 0.6; }
  100% { opacity: 1; }
}

.hero::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 80px;
  background: linear-gradient(to top, var(--color-bg), transparent);
}

.hero__content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 720px;
  margin: 0 auto;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-full);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: var(--space-6);
  backdrop-filter: blur(8px);
}

.hero__badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent);
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

.hero__title {
  font-size: var(--fs-4xl);
  font-weight: var(--fw-extrabold);
  color: white;
  line-height: var(--lh-tight);
  margin-bottom: var(--space-5);
  letter-spacing: -0.02em;
}

.hero__title-highlight {
  background: var(--gradient-result);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__subtitle {
  font-size: var(--fs-lg);
  color: rgba(255, 255, 255, 0.7);
  line-height: var(--lh-relaxed);
  margin-bottom: var(--space-8);
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

.hero__cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-4) var(--space-8);
  background: var(--gradient-primary);
  color: white;
  font-size: var(--fs-lg);
  font-weight: var(--fw-semibold);
  border-radius: var(--radius-xl);
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.3);
  transition: all var(--transition-base);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.hero__cta::after {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-shine);
  transform: translateX(-100%);
  transition: transform 0.6s ease;
}

.hero__cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.4);
  color: white;
}

.hero__cta:hover::after {
  transform: translateX(100%);
}

@media (min-width: 768px) {
  .hero__title {
    font-size: var(--fs-5xl);
  }
}

/* ============================================
   Section Styles
   ============================================ */
.section {
  padding: var(--space-16) 0;
}

.section--alt {
  background: var(--color-surface);
}

.section__header {
  text-align: center;
  max-width: 600px;
  margin: 0 auto var(--space-12);
}

.section__label {
  display: inline-block;
  font-size: var(--fs-sm);
  font-weight: var(--fw-semibold);
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-3);
}

.section__title {
  font-size: var(--fs-3xl);
  font-weight: var(--fw-bold);
  color: var(--color-text);
  line-height: var(--lh-tight);
  margin-bottom: var(--space-4);
}

.section__desc {
  font-size: var(--fs-lg);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
}

/* ============================================
   Tools Grid (Homepage)
   ============================================ */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
}

.tool-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-primary);
  transform: scaleX(0);
  transition: transform var(--transition-base);
  transform-origin: left;
}

.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: transparent;
  color: inherit;
}

.tool-card:hover::before {
  transform: scaleX(1);
}

.tool-card__icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-2xl);
  margin-bottom: var(--space-5);
  position: relative;
}

.tool-card__icon--blue {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.tool-card__icon--purple {
  background: var(--color-secondary-light);
  color: var(--color-secondary);
}

.tool-card__icon--green {
  background: var(--color-accent-light);
  color: var(--color-accent);
}

.tool-card__title {
  font-size: var(--fs-lg);
  font-weight: var(--fw-semibold);
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.tool-card__desc {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
}

.tool-card__arrow {
  position: absolute;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--color-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  transition: all var(--transition-base);
}

.tool-card:hover .tool-card__arrow {
  background: var(--color-primary);
  color: white;
  transform: translateX(3px);
}

/* ============================================
   Features Section
   ============================================ */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-6);
}

.feature-item {
  text-align: center;
  padding: var(--space-6);
}

.feature-item__icon {
  width: 56px;
  height: 56px;
  margin: 0 auto var(--space-4);
  background: var(--gradient-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-2xl);
  transition: all var(--transition-base);
}

.feature-item:hover .feature-item__icon {
  transform: scale(1.1) rotate(-3deg);
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-glow);
}

.feature-item__title {
  font-size: var(--fs-base);
  font-weight: var(--fw-semibold);
  margin-bottom: var(--space-2);
}

.feature-item__desc {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
}

/* ============================================
   Tool Page Layout
   ============================================ */
.tool-page {
  padding-top: var(--space-10);
  padding-bottom: var(--space-16);
}

.tool-page__header {
  text-align: center;
  margin-bottom: var(--space-10);
}

.tool-page__breadcrumb {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.tool-page__breadcrumb a {
  color: var(--color-text-secondary);
}

.tool-page__breadcrumb a:hover {
  color: var(--color-primary);
}

.tool-page__title {
  font-size: var(--fs-3xl);
  font-weight: var(--fw-bold);
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.tool-page__desc {
  font-size: var(--fs-lg);
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
  line-height: var(--lh-relaxed);
}

/* ============================================
   Calculator Card (Form Container)
   ============================================ */
.calc-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  box-shadow: var(--shadow-md);
  margin-bottom: var(--space-8);
}

.calc-card__title {
  font-size: var(--fs-xl);
  font-weight: var(--fw-semibold);
  margin-bottom: var(--space-6);
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.calc-card__title-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: var(--color-primary-light);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-lg);
}

/* ============================================
   Form Styles
   ============================================ */
.form-group {
  margin-bottom: var(--space-5);
}

.form-label {
  display: block;
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.form-label--required::after {
  content: ' *';
  color: var(--color-error);
}

.form-input,
.form-select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-lg);
  font-size: var(--fs-base);
  color: var(--color-text);
  background: var(--color-surface);
  transition: all var(--transition-fast);
  outline: none;
}

.form-input:hover,
.form-select:hover {
  border-color: var(--color-border-hover);
}

.form-input:focus,
.form-select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-input::placeholder {
  color: var(--color-text-muted);
}

.form-input--error {
  border-color: var(--color-error);
  background: var(--color-error-bg);
}

.form-input--error:focus {
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

.form-hint {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
}

.form-error {
  font-size: var(--fs-sm);
  color: var(--color-error);
  margin-top: var(--space-2);
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.form-error::before {
  content: '⚠';
  font-size: var(--fs-xs);
}

/* Dynamic component rows */
.component-row {
  display: grid;
  grid-template-columns: 1fr 100px 100px 40px;
  gap: var(--space-3);
  align-items: end;
  margin-bottom: var(--space-3);
  padding: var(--space-4);
  background: var(--color-surface-alt);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
  animation: slideIn 0.3s ease;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.component-row:hover {
  border-color: var(--color-border-hover);
}

.component-row .form-group {
  margin-bottom: 0;
}

.component-row .form-input {
  background: var(--color-surface);
}

@media (max-width: 640px) {
  .component-row {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2);
  }

  .component-row .form-group:first-child {
    grid-column: 1 / -1;
  }

  .component-row .btn-remove {
    grid-column: 2;
    justify-self: end;
  }
}

/* Course row for IPK (4 columns) */
.course-row {
  display: grid;
  grid-template-columns: 1fr 80px 120px 40px;
  gap: var(--space-3);
  align-items: end;
  margin-bottom: var(--space-3);
  padding: var(--space-4);
  background: var(--color-surface-alt);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
  animation: slideIn 0.3s ease;
}

.course-row:hover {
  border-color: var(--color-border-hover);
}

.course-row .form-group {
  margin-bottom: 0;
}

.course-row .form-input,
.course-row .form-select {
  background: var(--color-surface);
}

@media (max-width: 640px) {
  .course-row {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-2);
  }

  .course-row .form-group:first-child {
    grid-column: 1 / -1;
  }

  .course-row .btn-remove {
    grid-column: 2;
    justify-self: end;
  }
}

/* Weight bar */
.weight-bar {
  margin-top: var(--space-4);
  margin-bottom: var(--space-6);
}

.weight-bar__label {
  display: flex;
  justify-content: space-between;
  font-size: var(--fs-sm);
  margin-bottom: var(--space-2);
}

.weight-bar__value {
  font-weight: var(--fw-semibold);
  font-family: var(--font-mono);
}

.weight-bar__value--valid {
  color: var(--color-success);
}

.weight-bar__value--invalid {
  color: var(--color-error);
}

.weight-bar__track {
  height: 8px;
  background: var(--color-border);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.weight-bar__fill {
  height: 100%;
  border-radius: var(--radius-full);
  transition: width var(--transition-base), background var(--transition-base);
  background: var(--color-primary);
}

.weight-bar__fill--over {
  background: var(--color-error);
}

.weight-bar__fill--complete {
  background: var(--color-success);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-lg);
  font-size: var(--fs-base);
  font-weight: var(--fw-semibold);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  text-decoration: none;
  white-space: nowrap;
}

.btn--primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
}

.btn--primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.35);
}

.btn--primary:active {
  transform: translateY(0);
}

.btn--secondary {
  background: var(--color-surface);
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
}

.btn--secondary:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-50);
}

.btn--success {
  background: var(--color-accent);
  color: white;
}

.btn--success:hover {
  background: var(--color-accent-hover);
}

.btn--danger {
  background: var(--color-error-bg);
  color: var(--color-error);
  border: 1px solid var(--color-error-border);
}

.btn--danger:hover {
  background: var(--color-error);
  color: white;
}

.btn--lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--fs-lg);
  border-radius: var(--radius-xl);
}

.btn--sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--fs-sm);
}

.btn--block {
  width: 100%;
}

.btn-remove {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  color: var(--color-text-muted);
  border: 1px solid transparent;
  transition: all var(--transition-fast);
  font-size: var(--fs-lg);
  flex-shrink: 0;
  align-self: center;
}

.btn-remove:hover {
  background: var(--color-error-bg);
  color: var(--color-error);
  border-color: var(--color-error-border);
}

.btn-group {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
}

/* ============================================
   Result Card
   ============================================ */
.result-card {
  background: var(--color-surface);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  margin-top: var(--space-8);
  position: relative;
  overflow: hidden;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-lg);
  display: none;
}

.result-card.visible {
  display: block;
  animation: resultReveal 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes resultReveal {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.98);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.result-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient-result);
}

.result-card__title {
  font-size: var(--fs-lg);
  font-weight: var(--fw-semibold);
  margin-bottom: var(--space-6);
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.result-card__main {
  text-align: center;
  padding: var(--space-6) 0;
  margin-bottom: var(--space-6);
  background: var(--gradient-card);
  border-radius: var(--radius-xl);
}

.result-card__score {
  font-size: var(--fs-5xl);
  font-weight: var(--fw-extrabold);
  font-family: var(--font-mono);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: var(--space-2);
}

.result-card__predicate {
  font-size: var(--fs-xl);
  font-weight: var(--fw-semibold);
  color: var(--color-text);
}

.result-card__status {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  font-size: var(--fs-sm);
  font-weight: var(--fw-semibold);
  margin-top: var(--space-3);
}

.result-card__status--success {
  background: var(--color-success-bg);
  color: var(--color-success);
}

.result-card__status--warning {
  background: var(--color-warning-bg);
  color: var(--color-warning);
}

.result-card__status--danger {
  background: var(--color-error-bg);
  color: var(--color-error);
}

.result-card__status--info {
  background: var(--color-info-bg);
  color: var(--color-info);
}

.result-card__details {
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-6);
}

.result-card__detail-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--color-border);
  font-size: var(--fs-sm);
}

.result-card__detail-row:last-child {
  border-bottom: none;
}

.result-card__detail-label {
  color: var(--color-text-secondary);
}

.result-card__detail-value {
  font-weight: var(--fw-semibold);
  font-family: var(--font-mono);
}

/* ============================================
   Mode Toggle (for Raport)
   ============================================ */
.mode-toggle {
  display: flex;
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  padding: var(--space-1);
  margin-bottom: var(--space-6);
  border: 1px solid var(--color-border);
}

.mode-toggle__btn {
  flex: 1;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text-secondary);
  background: transparent;
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  text-align: center;
}

.mode-toggle__btn.active {
  background: var(--color-surface);
  color: var(--color-primary);
  font-weight: var(--fw-semibold);
  box-shadow: var(--shadow-sm);
}

/* Scheme selector (for Konversi) */
.scheme-tabs {
  display: flex;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
  flex-wrap: wrap;
}

.scheme-tab {
  padding: var(--space-2) var(--space-5);
  border-radius: var(--radius-full);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text-secondary);
  background: var(--color-surface);
  border: 1.5px solid var(--color-border);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.scheme-tab.active {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

.scheme-tab:hover:not(.active) {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ============================================
   Tabs (for IPK)
   ============================================ */
.tabs {
  display: flex;
  border-bottom: 2px solid var(--color-border);
  margin-bottom: var(--space-8);
  gap: var(--space-1);
}

.tab {
  padding: var(--space-3) var(--space-6);
  font-size: var(--fs-base);
  font-weight: var(--fw-medium);
  color: var(--color-text-secondary);
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  cursor: pointer;
  transition: all var(--transition-fast);
  background: transparent;
  border-top: none;
  border-left: none;
  border-right: none;
}

.tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
  font-weight: var(--fw-semibold);
}

.tab:hover:not(.active) {
  color: var(--color-text);
  border-bottom-color: var(--color-border-hover);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ============================================
   Custom scheme table editor
   ============================================ */
.scheme-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  font-size: var(--fs-sm);
}

.scheme-table th {
  background: var(--color-surface-alt);
  padding: var(--space-3) var(--space-4);
  text-align: left;
  font-weight: var(--fw-semibold);
  color: var(--color-text-secondary);
  border-bottom: 1px solid var(--color-border);
}

.scheme-table td {
  padding: var(--space-2) var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

.scheme-table tr:last-child td {
  border-bottom: none;
}

.scheme-table .form-input {
  padding: var(--space-2);
  font-size: var(--fs-sm);
}

/* ============================================
   Ad Slot Placeholder
   ============================================ */
.ad-slot {
  background: var(--color-surface-alt);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6) var(--space-4);
  text-align: center;
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  margin: var(--space-8) 0;
}

/* ============================================
   SEO Content Section
   ============================================ */
.seo-content {
  margin-top: var(--space-12);
}

.seo-content__section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  margin-bottom: var(--space-6);
}

.seo-content__title {
  font-size: var(--fs-xl);
  font-weight: var(--fw-semibold);
  margin-bottom: var(--space-4);
  color: var(--color-text);
}

.seo-content__text {
  font-size: var(--fs-base);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
}

.seo-content__text p {
  margin-bottom: var(--space-4);
}

.seo-content__text ul,
.seo-content__text ol {
  margin-bottom: var(--space-4);
  padding-left: var(--space-6);
}

.seo-content__text ul {
  list-style: disc;
}

.seo-content__text ol {
  list-style: decimal;
}

.seo-content__text li {
  margin-bottom: var(--space-2);
}

.seo-content__text code {
  font-family: var(--font-mono);
  background: var(--color-surface-alt);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
}

/* Example box */
.example-box {
  background: var(--color-primary-50);
  border: 1px solid var(--color-primary-light);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  margin: var(--space-4) 0;
  font-size: var(--fs-sm);
  font-family: var(--font-mono);
  line-height: var(--lh-relaxed);
  color: var(--color-text);
}

/* ============================================
   FAQ Accordion
   ============================================ */
.faq-list {
  max-width: var(--container-narrow);
  margin: 0 auto;
}

.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-3);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--color-border-hover);
}

.faq-item.open {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-sm);
}

.faq-question {
  width: 100%;
  padding: var(--space-5) var(--space-6);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  font-size: var(--fs-base);
  font-weight: var(--fw-medium);
  color: var(--color-text);
  text-align: left;
  cursor: pointer;
  background: transparent;
  border: none;
}

.faq-question:hover {
  color: var(--color-primary);
}

.faq-icon {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--color-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  transition: all var(--transition-base);
  flex-shrink: 0;
}

.faq-item.open .faq-icon {
  background: var(--color-primary-light);
  color: var(--color-primary);
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow);
}

.faq-answer__inner {
  padding: 0 var(--space-6) var(--space-5);
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
}

/* ============================================
   Related Tools
   ============================================ */
.related-tools {
  margin-top: var(--space-10);
}

.related-tools__title {
  font-size: var(--fs-lg);
  font-weight: var(--fw-semibold);
  margin-bottom: var(--space-6);
  text-align: center;
}

.related-tools__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-4);
}

.related-tool-card {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition-fast);
}

.related-tool-card:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-50);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  color: inherit;
}

.related-tool-card__icon {
  font-size: var(--fs-xl);
}

.related-tool-card__text {
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background: var(--gradient-hero);
  padding: var(--space-12) 0 var(--space-6);
  color: rgba(255, 255, 255, 0.7);
}

.footer__grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(2, 1fr);
  gap: var(--space-10);
  margin-bottom: var(--space-10);
}

@media (max-width: 640px) {
  .footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }
}

.footer__brand {
  font-size: var(--fs-xl);
  font-weight: var(--fw-bold);
  color: white;
  margin-bottom: var(--space-3);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.footer__desc {
  font-size: var(--fs-sm);
  line-height: var(--lh-relaxed);
}

.footer__title {
  font-size: var(--fs-sm);
  font-weight: var(--fw-semibold);
  color: white;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-4);
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer__link {
  font-size: var(--fs-sm);
  color: rgba(255, 255, 255, 0.6);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: white;
}

.footer__bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-6);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--fs-xs);
  flex-wrap: wrap;
  gap: var(--space-3);
}

.footer__copy {
  color: rgba(255, 255, 255, 0.5);
}

/* ============================================
   Alert / Error Box
   ============================================ */
.alert {
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-lg);
  font-size: var(--fs-sm);
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
  animation: fadeIn 0.3s ease;
}

.alert--error {
  background: var(--color-error-bg);
  border: 1px solid var(--color-error-border);
  color: var(--color-error);
}

.alert--success {
  background: var(--color-success-bg);
  border: 1px solid var(--color-accent-light);
  color: var(--color-accent);
}

.alert--info {
  background: var(--color-info-bg);
  border: 1px solid var(--color-primary-light);
  color: var(--color-primary);
}

/* ============================================
   Utilities
   ============================================ */
.text-center { text-align: center; }
.text-mono { font-family: var(--font-mono); }
.font-semibold { font-weight: var(--fw-semibold); }
.font-bold { font-weight: var(--fw-bold); }
.text-sm { font-size: var(--fs-sm); }
.text-muted { color: var(--color-text-secondary); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.gap-3 { gap: var(--space-3); }
.hidden { display: none !important; }

/* Visually hidden for SR */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Focus visible */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ============================================
   Legal Pages & Extra UI
   ============================================ */
.legal-content {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  box-shadow: var(--shadow-sm);
  margin-bottom: var(--space-10);
}

.legal-content h2 {
  font-size: var(--fs-xl);
  color: var(--color-text);
  margin-top: var(--space-8);
  margin-bottom: var(--space-4);
}

.legal-content p, .legal-content ul {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
  line-height: 1.7;
}

.legal-content ul {
  padding-left: var(--space-6);
  list-style: disc;
}

.tool-card__badge {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  background: var(--color-primary);
  color: white;
  font-size: var(--fs-xs);
  font-weight: var(--fw-bold);
  padding: 4px 8px;
  border-radius: var(--radius-full);
  z-index: 1;
}

.btn-group {
  display: flex;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
  justify-content: flex-end;
}

@media (max-width: 480px) {
  .btn-group {
    flex-direction: column;
    justify-content: stretch;
  }
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 480px) {
  :root {
    --fs-3xl: 1.5rem;
    --fs-4xl: 1.875rem;
    --fs-5xl: 2.25rem;
  }

  .hero {
    padding: var(--space-12) 0 var(--space-16);
  }

  .section {
    padding: var(--space-10) 0;
  }

  .calc-card {
    padding: var(--space-5);
  }

  .result-card {
    padding: var(--space-5);
  }

  .seo-content__section {
    padding: var(--space-5);
  }
}