/* styles.css
   Phase 6 Section 1:
   Consistent design system for typography, color palette,
   spacing scale, and reusable UI patterns.

   Phase 6 Section 2:
   Responsive UI refinement, mobile navbar polish,
   accessibility improvements, lightweight interaction support,
   and image consistency across cards and detail pages.

   Phase 6 Section 3:
   Performance cleanup, CSS simplification,
   and class-based interaction states.
*/

:root {
  --page-max-width: 1120px;

  /* Color palette */
  --color-primary: #1f2937;
  --color-primary-soft: #374151;
  --color-accent: #2563eb;
  --color-accent-soft: #dbeafe;

  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-surface-muted: #f1f5f9;

  --color-text: #111827;
  --color-text-muted: #6b7280;
  --color-border: #dbe1ea;

  --color-success-bg: #ecfdf3;
  --color-success-border: #a7f3d0;

  --color-warning-bg: #fffbeb;
  --color-warning-border: #fde68a;

  --color-danger-bg: #fef2f2;
  --color-danger-border: #fecaca;

  /* Typography */
  --font-size-body: 1rem;
  --font-size-small: 0.875rem;
  --font-size-h1: clamp(2rem, 3vw, 2.75rem);
  --font-size-h2: clamp(1.5rem, 2.2vw, 2rem);
  --font-size-h3: 1.125rem;

  --line-height-body: 1.7;
  --line-height-heading: 1.2;

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4rem;

  /* Radius / shadows */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;

  --shadow-sm: 0 4px 14px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 10px 30px rgba(15, 23, 42, 0.08);
}

/* ==========================================
   Global base
========================================== */

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
}

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

p,
ul,
ol {
  color: var(--color-text-muted);
}

strong {
  color: var(--color-text);
}

small,
.form-text,
.text-muted,
.small {
  font-size: var(--font-size-small);
}

/* ==========================================
   Accessibility / focus states
========================================== */

a:focus-visible,
button:focus-visible,
.btn:focus-visible,
.form-control:focus-visible,
.form-select:focus-visible,
.navbar-toggler:focus-visible,
.detail-media-trigger:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.28);
  outline-offset: 2px;
}

/* ==========================================
   Typography hierarchy
========================================== */

h1 {
  font-size: var(--font-size-h1);
  line-height: var(--line-height-heading);
  letter-spacing: -0.02em;
  font-weight: 700;
  color: var(--color-text);
}

h2 {
  font-size: var(--font-size-h2);
  line-height: 1.25;
  letter-spacing: -0.01em;
  font-weight: 650;
  color: var(--color-text);
}

h3,
.h4,
.h5 {
  line-height: 1.3;
  color: var(--color-text);
}

.section-intro {
  max-width: 720px;
  font-size: 1.05rem;
}

.eyebrow {
  display: inline-block;
  margin-bottom: var(--space-2);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
}

/* ==========================================
   Layout helpers
========================================== */

.page-section {
  margin-bottom: var(--space-7);
}

.section-heading {
  margin-bottom: var(--space-4);
}

.section-header {
  max-width: 760px;
}

.section-header--centered {
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

/* ==========================================
   Surfaces / cards
========================================== */

.surface-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.surface-card-muted {
  background-color: var(--color-surface-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

/* ==========================================
   Links
========================================== */

a {
  color: var(--color-accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.link-subtle {
  color: var(--color-text-muted);
}

.link-subtle:hover {
  color: var(--color-text);
  text-decoration: none;
}

/* ==========================================
   Navigation
========================================== */

.site-header {
  background-color: rgba(248, 250, 252, 0.88);
  backdrop-filter: blur(10px);
}

.navbar {
  padding-top: 0.9rem;
  padding-bottom: 0.9rem;
}

.navbar-brand {
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.navbar-toggler {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 0.45rem 0.7rem;
  box-shadow: none;
}

.navbar-toggler:hover {
  background-color: var(--color-surface-muted);
}

.navbar-toggler:focus {
  box-shadow: 0 0 0 0.2rem rgba(37, 99, 235, 0.12);
}

.nav-link {
  color: var(--color-text-muted);
  font-weight: 500;
  transition: color 0.2s ease;
}

.nav-link:hover,
.nav-link:focus {
  color: var(--color-text);
  text-decoration: none;
}

.nav-link.active {
  color: var(--color-text);
}

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

.btn {
  border-radius: 999px;
  font-weight: 600;
  padding: 0.65rem 1.05rem;
  transition:
    box-shadow 0.18s ease,
    background-color 0.18s ease,
    border-color 0.18s ease;
}

.btn:hover {
  text-decoration: none;
}

.btn-dark {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-dark:hover,
.btn-dark:focus {
  background-color: var(--color-primary-soft);
  border-color: var(--color-primary-soft);
  box-shadow: var(--shadow-sm);
}

.btn-outline-dark {
  color: var(--color-primary);
  border-color: var(--color-border);
  background-color: var(--color-surface);
}

.btn-outline-dark:hover,
.btn-outline-dark:focus {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background-color: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

/* ==========================================
   Forms
========================================== */

.form-control,
.form-select {
  border-radius: var(--radius-md);
  border-color: var(--color-border);
  padding: 0.8rem 0.95rem;
  box-shadow: none;
}

.form-control:focus,
.form-select:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 0.2rem rgba(37, 99, 235, 0.12);
}

.form-label {
  font-weight: 600;
  color: var(--color-text);
}

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

.form-field {
  margin-bottom: var(--space-4);
}

/* ==========================================
   Alerts
========================================== */

.alert {
  border-radius: var(--radius-md);
  border-width: 1px;
  box-shadow: var(--shadow-sm);
}

.alert-success {
  background-color: var(--color-success-bg);
  border-color: var(--color-success-border);
  color: #166534;
}

.alert-warning {
  background-color: var(--color-warning-bg);
  border-color: var(--color-warning-border);
  color: #92400e;
}

.alert-danger {
  background-color: var(--color-danger-bg);
  border-color: var(--color-danger-border);
  color: #991b1b;
}

/* ==========================================
   Badges / pills
========================================== */

.badge {
  border-radius: 999px;
  padding: 0.55em 0.8em;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.text-bg-dark {
  background-color: var(--color-primary) !important;
}

.text-bg-secondary {
  background-color: #e5e7eb !important;
  color: var(--color-primary) !important;
}

/* ==========================================
   Project cards
========================================== */

.project-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease,
    border-color 0.2s ease;
}

.project-card:hover {
  transform: translateY(-4px);
  border-color: #cbd5e1;
  box-shadow: var(--shadow-md);
}

.project-card-img {
  display: block;
  width: 100%;
  height: 260px;
  object-fit: cover;
  object-position: center;
  border-top-left-radius: calc(var(--radius-lg) - 1px);
  border-top-right-radius: calc(var(--radius-lg) - 1px);
}

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

/* ==========================================
   Project detail media
========================================== */

.detail-media-trigger {
  display: block;
  width: 100%;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: zoom-in;
  text-align: inherit;
}

.detail-media-image {
  display: block;
  width: 100%;
  height: auto;
  object-fit: contain;
  box-shadow: var(--shadow-sm);
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}

.detail-media-trigger:hover .detail-media-image {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.detail-image-modal {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

#imagePreviewModalImg {
  display: block;
  width: 100%;
  height: auto;
  object-fit: contain;
  max-height: 75vh;
}

/* ==========================================
   Lists / metadata
========================================== */

.info-list {
  list-style: none;
  padding-left: 0;
  margin-bottom: 0;
}

.info-list li + li {
  margin-top: var(--space-3);
}

.meta-label {
  display: inline-block;
  min-width: 64px;
  font-weight: 600;
  color: var(--color-text);
}

/* ==========================================
   Scroll to top button
========================================== */

.scroll-to-top-btn {
  position: fixed;
  left: 50%;
  transform: translateX(-50%);
  bottom: 1.25rem;
  display: none;
  z-index: 1000;
  min-width: 48px;
  min-height: 48px;
  padding: 0.75rem 0.95rem;
  box-shadow: var(--shadow-md);
  transition: transform 0.2s ease;
}

.scroll-to-top-btn.is-visible {
  display: block;
}

.scroll-to-top-btn:hover {
  transform: translateX(-50%) translateY(-6px);
}

/* ==========================================
   Footer
========================================== */

.site-footer {
  background-color: var(--color-surface);
}

.footer-link-row a {
  font-weight: 500;
}

/* ==========================================
   Contact form anti-spam honeypot
========================================== */

.contact-honeypot {
  position: absolute !important;
  left: -9999px !important;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

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

@media (max-width: 991.98px) {
  .section-intro {
    max-width: 100%;
  }

  .navbar-collapse {
    margin-top: var(--space-3);
    padding: var(--space-3);
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
  }

  .navbar-nav {
    gap: 0.35rem !important;
  }

  .nav-link {
    padding: 0.7rem 0.85rem;
    border-radius: var(--radius-md);
  }

  .nav-link:hover,
  .nav-link:focus {
    background-color: var(--color-surface-muted);
  }

  .project-card-img {
    height: 240px;
  }
}

@media (max-width: 767.98px) {
  .page-section {
    margin-bottom: var(--space-6);
  }

  .project-card-img {
    height: 220px;
  }

  .btn {
    padding: 0.6rem 1rem;
  }

  main .container {
    padding-top: 2rem !important;
    padding-bottom: 2rem !important;
  }

  .scroll-to-top-btn {
    bottom: 1rem;
  }
}

@media (max-width: 575.98px) {
  .navbar-brand {
    font-size: 1.5rem;
  }

  .eyebrow {
    display: block;
  }

  .section-intro {
    font-size: 1rem;
  }

  .project-card .card-body {
    padding: var(--space-4);
  }

  .project-card-img {
    height: 210px;
  }

  .scroll-to-top-btn {
    min-width: 44px;
    min-height: 44px;
    padding: 0.65rem 0.85rem;
  }
}