:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --surface-alt: #f7f7f9;
  --text: #171717;
  --text-muted: #6b6b73;
  --border: #e6e6ea;
  --accent: #10a37f;
  --accent-dark: #0d8a69;
  --accent-soft: #e3f7f1;
  --shadow: 0 10px 30px rgba(23, 23, 23, 0.08);
  --radius: 16px;
  --header-h: 64px;
}

[data-theme="dark"] {
  --bg: #0f1012;
  --surface: #17181b;
  --surface-alt: #1e2024;
  --text: #f2f2f4;
  --text-muted: #a1a1aa;
  --border: #2a2c31;
  --accent: #25c69a;
  --accent-dark: #1fb087;
  --accent-soft: #16332c;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background 0.3s ease, color 0.3s ease;
}

a {
  color: inherit;
  text-decoration: none;
}

h1, h2, h3, p {
  margin: 0;
}

/* ===== HEADER ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}

.site-nav {
  max-width: 1180px;
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 19px;
  letter-spacing: -0.02em;
}

.brand-mark {
  width: 22px;
  height: 22px;
  background: var(--accent);
  border-radius: 6px;
  position: relative;
}

.brand-mark::after {
  content: "";
  position: absolute;
  inset: 6px;
  border-radius: 2px;
  background: var(--bg);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-list {
  display: flex;
  gap: 26px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text-muted);
  padding: 6px 2px;
  transition: color 0.2s ease;
}

.nav-list a:hover,
.nav-list a[aria-current="page"] {
  color: var(--text);
}

.nav-list a[aria-current="page"] {
  position: relative;
}

.nav-list a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -6px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
}

.theme-switch {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 5px;
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: 10px;
}

.theme-switch-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  margin-right: 2px;
}

.theme-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 0;
  background: transparent;
  color: var(--text-muted);
  font: inherit;
  font-size: 12.5px;
  font-weight: 600;
  padding: 5px 10px;
  border-radius: 7px;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease;
}

.theme-btn:hover {
  color: var(--text);
}

.theme-btn[aria-pressed="true"] {
  background: var(--accent);
  color: #fff;
}

.theme-icon {
  width: 14px;
  height: 14px;
  display: inline-block;
}

.theme-icon-sun {
  border: 2px solid currentColor;
  border-radius: 50%;
}

.theme-icon-moon {
  border-radius: 50% 0 50% 50%;
  transform: rotate(-45deg);
}

/* ===== MAIN ===== */
main {
  max-width: 1180px;
  margin: 0 auto;
  padding: 48px 24px 72px;
}

/* ===== INTRO ===== */
.intro {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px;
}

.eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
}

.section-title {
  font-size: clamp(30px, 5vw, 46px);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
}

.section-title-lg {
  font-size: clamp(34px, 6vw, 54px);
}

.intro-copy {
  margin-top: 18px;
  font-size: 17px;
  color: var(--text-muted);
}

/* ===== SECTION ===== */
.section {
  margin-top: 60px;
}

.section-kicker {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 26px;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 22px;
}

/* ===== APP CARD ===== */
.app-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.app-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: color-mix(in srgb, var(--accent) 40%, var(--border));
}

.app-card-icon {
  width: 60px;
  height: 60px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  margin-bottom: 20px;
}

.app-card-icon svg {
  width: 100%;
  height: 100%;
}

.app-card-title {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 10px;
}

.app-card-desc {
  font-size: 14.5px;
  color: var(--text-muted);
  flex-grow: 1;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font: inherit;
  font-weight: 700;
  font-size: 14px;
  padding: 12px 20px;
  border-radius: 10px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background 0.2s ease, color 0.2s ease, transform 0.15s ease;
}

.btn:active {
  transform: translateY(1px);
}

.btn-ghost {
  background: var(--surface-alt);
  color: var(--text);
  border-color: var(--border);
  margin-top: 22px;
}

.btn-ghost:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.btn-sm {
  padding: 9px 16px;
  font-size: 13px;
}

/* ===== SECTION NOTE ===== */
.section-note {
  margin-top: 28px;
  font-size: 15px;
  color: var(--text-muted);
  text-align: center;
}

.section-note a {
  color: var(--accent);
  text-decoration: underline;
}

/* Microsoft Store badge — show light version in light theme, dark in dark theme */
.store-badge .badge-dark { display: none; }
[data-theme="dark"] .store-badge .badge-light { display: none; }
[data-theme="dark"] .store-badge .badge-dark { display: block; }
.store-badge { display: inline-block; margin-top: 22px; }

/* ===== CONTACT FORM STYLES ===== */
.contact-form {
  width: 100%;
  max-width: 600px;
  margin-top: 20px;
  background: var(--surface-alt);
  padding: 30px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  display: block; 
  box-sizing: border-box;
}

.form-group {
  margin-bottom: 20px;
  display: flex;
  flex-direction: column;
  width: 100%; 
}

.form-group label {
  font-weight: 600;
  margin-bottom: 8px;
  font-size: 14.5px;
  color: var(--text);
  text-shadow: none;
}

.contact-form input[type="text"],
.contact-form input[type="email"],
.contact-form textarea {
  width: 100% !important;
  box-sizing: border-box !important;
  padding: 12px;
  border: 1px solid var(--border) !important;
  border-radius: 8px;
  background-color: var(--bg) !important;
  color: var(--text) !important;
  font-family: inherit;
  font-size: 15px;
  transition: border-color 0.2s ease;
  display: block;
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--accent) !important;
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.contact-form textarea {
  resize: vertical;
  min-height: 120px; 
}

.contact-form .btn-primary {
  width: auto;
  display: inline-block;
  background: var(--accent);
  color: #ffffff;
  border: none;
  cursor: pointer;
}