/* CSS Style-Sheet – IT Abteilung, Institut für Mathematik, HU Berlin
   Corporate Design HU Berlin | Responsive, mobile-first */

/* ================================================================
   CSS CUSTOM PROPERTIES (HU Corporate Design)
   ================================================================ */
:root {
  --hu-blue:      #00376C;   /* Primärfarbe: RGB 0,55,108 – Pantone 294 */
  --hu-blue-dark: #002650;
  --hu-blue-mid:  #1a5a9a;   /* mittleres Blau für Hover */
  --hu-light:     #ccd6e0;   /* Sekundär hell */
  --hu-bg:        #f5f5f0;   /* Hintergrund leicht beige-weiß */
  --hu-white:     #ffffff;
  --hu-border:    #d1d1c2;
  --space-xs:     0.25rem;
  --space-sm:     0.5rem;
  --space-md:     1rem;
  --space-lg:     1.5rem;
  --space-xl:     2rem;
  --radius:       6px;
  --shadow-sm:    0 1px 3px rgba(0,0,0,.1);
  --shadow-md:    0 4px 12px rgba(0,0,0,.12);
}

/* ================================================================
   RESET & BASE
   ================================================================ */
*, *::before, *::after {
  box-sizing: border-box;
}

body, table, p, h1, h2, h3, h4 {
  font-family: "Verdana", sans-serif;
  color: #000000;
}

body {
  font-size: 15px;
  line-height: 1.6;
  background-color: var(--hu-bg);
  margin: 0;
  padding: 0;
}

/* ================================================================
   TYPOGRAPHY
   ================================================================ */
h1 { font-size: 1.8rem;  text-align: left; color: var(--hu-blue); margin-top: 0.5em; }
h2 { font-size: 1.3rem;  font-weight: bold; text-align: left; }
h3 { font-size: 1.1rem;  font-weight: bold; text-align: left; }
h4 { font-weight: bold; }
hr { background-color: #808080; height: 2px; border: none; }

/* ================================================================
   LINKS
   ================================================================ */
a { text-decoration: none; color: var(--hu-blue); }
a:visited { color: var(--hu-blue); }
a:hover { background-color: var(--hu-light); }

a.anker    { color: #000000; }
a.ankerh2  { text-decoration: none; font-size: 1.3rem; font-weight: bold; color: #000000; }
a.ankerh4  { color: #000000; font-weight: bold; text-decoration: none; }
a.ankerh2:hover, a.anker:hover, a.ankerh3:hover, a.ankerh4:hover, a.img:hover {
  background-color: transparent;
}
a.Imprint { font-size: 10px; }

/* ================================================================
   OUTER WRAPPER
   ================================================================ */
.aussenrahmen {
  background-color: var(--hu-white);
  border-left: 2px solid var(--hu-border);
  border-right: 2px solid var(--hu-border);
  margin: 0 auto;
  max-width: 1200px;
}

/* ================================================================
   STICKY HEADER
   ================================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--hu-white);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

/* Logo + title row */
.header-top {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background: var(--hu-white);
}

.logo-link img {
  height: 75px;
  width: auto;
  display: block;
  border: none;
}

.header-brand {
  flex: 1;
}

.header-institute {
  font-size: 11px;
  color: var(--hu-blue);
  margin-bottom: 0.25em;
}

.header-institute a {
  color: var(--hu-blue);
  text-decoration: none;
}
.header-institute a:hover {
  background-color: transparent;
  text-decoration: underline;
}

.header-title {
  font-size: 1.4em;
  font-weight: bold;
  color: var(--hu-blue);
  font-family: "Verdana", sans-serif;
  line-height: 1.2;
}

/* Language switcher in header */
.header-lang {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

/* Mobile hamburger button */
.nav-toggle {
  display: none;
  background: var(--hu-white);
  color: var(--hu-blue);
  border: 1px solid var(--hu-blue);
  padding: 0.4em 0.7em;
  font-size: 1.2rem;
  cursor: pointer;
  flex-shrink: 0;
  font-family: "Verdana", sans-serif;
  border-radius: 3px;
  transition: background 0.15s;
}

.nav-toggle:hover {
  background: var(--hu-light);
}

/* ================================================================
   MAIN NAVIGATION
   ================================================================ */
.main-nav {
  background: var(--hu-white);
  border-bottom: 3px solid var(--hu-blue);
}

.main-nav > ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
}

.main-nav li {
  margin: 0;
}

/* Top-level links */
.main-nav > ul > li > a {
  display: block;
  padding: 0.55rem 1.1rem;
  color: var(--hu-blue);
  text-decoration: none;
  font-size: 0.9rem;
  line-height: 1.4;
  white-space: nowrap;
  transition: background 0.15s, color 0.15s;
}

.main-nav > ul > li > a:hover {
  background: var(--hu-light);
  color: var(--hu-blue);
}

.main-nav > ul > li.active > a {
  background: var(--hu-blue);
  color: var(--hu-white);
  font-weight: bold;
}

.main-nav > ul > li.active > a:hover {
  background: var(--hu-blue-dark);
  color: var(--hu-white);
}

/* ================================================================
   DROPDOWN NAVIGATION
   ================================================================ */
.nav-item {
  position: relative;
}

.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  display: none;
  min-width: 220px;
  background: var(--hu-white);
  border: 1px solid var(--hu-border);
  border-top: 3px solid var(--hu-blue);
  box-shadow: var(--shadow-md);
  z-index: 999;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-item:hover .nav-dropdown,
.nav-item:focus-within .nav-dropdown,
.nav-item.open .nav-dropdown {
  display: block;
}

.nav-dropdown li a {
  display: block;
  padding: 0.45rem 1rem;
  color: var(--hu-blue);
  font-size: 0.875rem;
  text-decoration: none;
  border-bottom: 1px solid var(--hu-border);
  transition: background 0.15s;
}

.nav-dropdown li:last-child a {
  border-bottom: none;
}

.nav-dropdown li a:hover {
  background: var(--hu-light);
  color: var(--hu-blue);
}

.nav-dropdown li.active-sub > a {
  font-weight: bold;
  background: var(--hu-light);
  color: var(--hu-blue);
}

.nav-caret {
  font-size: 0.7em;
  margin-left: 0.2em;
  opacity: 0.85;
}

/* ================================================================
   CONTENT AREA
   ================================================================ */
.content-area {
  background: var(--hu-white);
  padding: var(--space-md) 1.2rem var(--space-xl);
  min-height: 400px;
}

/* Language switcher (shared styles for header and wherever used) */
.lang-switcher {
  display: inline-flex;
  border: 1px solid var(--hu-border);
  border-radius: var(--radius);
  overflow: hidden;
}

.lang-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.25rem 0.6rem;
  font-size: 0.8rem;
  font-family: "Verdana", sans-serif;
  color: var(--hu-blue);
  text-decoration: none;
  background: var(--hu-white);
  border: none;
  line-height: 1.4;
}

.lang-btn + .lang-btn {
  border-left: 1px solid var(--hu-border);
}

.lang-btn:hover {
  background: var(--hu-light);
  color: var(--hu-blue);
}

.lang-btn.active {
  background: var(--hu-blue);
  color: var(--hu-white);
  font-weight: bold;
  cursor: default;
}

.lang-btn.active:hover {
  background: var(--hu-blue);
  color: var(--hu-white);
}

/* ================================================================
   HERO SECTION (Startseite)
   ================================================================ */
.hero {
  background: linear-gradient(135deg, var(--hu-blue) 0%, var(--hu-blue-mid) 100%);
  color: var(--hu-white);
  padding: var(--space-xl) var(--space-lg);
  margin: -0.8rem -1.2rem var(--space-xl);
}

.hero h1 {
  color: var(--hu-white);
  font-size: 1.6rem;
  margin: 0 0 var(--space-sm);
}

.hero p {
  font-size: 1rem;
  margin: 0;
  color: var(--hu-white);
}

/* ================================================================
   ICON CARDS (Startseite Schnellzugriff)
   ================================================================ */
.icon-card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(200px, 100%), 1fr));
  gap: var(--space-sm);
  margin: var(--space-md) 0 var(--space-lg);
}

.icon-card {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  padding: var(--space-md);
  border: 1px solid var(--hu-border);
  border-radius: var(--radius);
  text-decoration: none;
  color: inherit;
  background: var(--hu-white);
  transition: box-shadow 0.2s, border-color 0.2s;
}

.icon-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--hu-blue);
  background: var(--hu-white);
}

.icon-card__icon {
  color: var(--hu-blue);
  flex-shrink: 0;
  margin-top: 2px;
}

.icon-card__text {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.icon-card__text strong {
  font-size: 0.9rem;
  color: var(--hu-blue);
  display: block;
}

.icon-card__text span {
  font-size: 0.8rem;
  color: #555;
  line-height: 1.4;
}

/* ================================================================
   SUPPORT TILES (Hilfe anfragen – reines HTML)
   ================================================================ */
.support-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(240px, 100%), 240px));
  gap: var(--space-md);
  margin: var(--space-md) 0 var(--space-lg);
  justify-content: start;
}

.support-tile {
  border: 1px solid var(--hu-border);
  border-top: 3px solid var(--hu-blue);
  border-radius: var(--radius);
  padding: var(--space-md);
  background: var(--hu-white);
  box-shadow: var(--shadow-sm);
}

.support-tile h3 {
  margin: 0 0 var(--space-sm);
  font-size: 1rem;
  font-weight: bold;
  color: var(--hu-blue);
  line-height: 1.3;
}

.support-tile a {
  color: var(--hu-blue);
  text-decoration: none;
}

.support-tile a:hover {
  text-decoration: underline;
  background-color: transparent;
}

.support-tile p {
  margin: var(--space-sm) 0 0;
  font-size: 0.875rem;
  line-height: 1.5;
}

/* ================================================================
   INFO / WARNING BOXES
   ================================================================ */
.info-box {
  background: var(--hu-light);
  border-left: 4px solid var(--hu-blue);
  padding: 0.7rem 1.1rem;
  margin: var(--space-md) 0;
}

.warning-box {
  background: #fff8e1;
  border-left: 4px solid #e6a800;
  padding: 0.7rem 1.1rem;
  margin: var(--space-md) 0;
}

/* ================================================================
   QUICK-LINK CARDS (Übersichtsseiten)
   ================================================================ */
.quick-link-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(240px, 100%), 240px));
  gap: var(--space-md);
  margin: var(--space-lg) 0;
  justify-content: start;
}

.quick-link-card {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding: 0.85rem 1rem;
  border: 1px solid var(--hu-border);
  border-top: 3px solid var(--hu-blue);
  border-radius: var(--radius);
  background: var(--hu-white);
  color: var(--hu-blue);
  text-decoration: none;
  transition: background 0.15s, box-shadow 0.2s;
}

.quick-link-card:hover {
  background: var(--hu-light);
  color: var(--hu-blue);
  box-shadow: var(--shadow-sm);
}

.quick-link-card strong {
  font-size: 0.95rem;
  display: block;
}

.quick-link-card span {
  font-size: 0.82rem;
  color: #444;
}

/* ================================================================
   CODE / PRE / KBD / TT
   ================================================================ */
pre {
  background: #1e1e1e;
  color: #d4d4d4;
  padding: 0.8rem 1rem;
  border-radius: var(--radius);
  overflow-x: auto;
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.82rem;
  line-height: 1.55;
  margin: 0.8rem 0;
}

pre code {
  background: transparent;
  padding: 0;
  border: none;
  font-size: inherit;
  color: inherit;
}

code, tt {
  background: #f0f0f0;
  padding: 1px 4px;
  border-radius: 2px;
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.88em;
}

kbd {
  background: #f5f5f5;
  border: 1px solid #ccc;
  border-bottom-width: 2px;
  border-radius: 3px;
  padding: 1px 6px;
  font-size: 0.85em;
  font-family: 'Courier New', Courier, monospace;
}

/* ================================================================
   IMAGES
   ================================================================ */
img {
  max-width: 100%;
  height: auto;
}

/* ================================================================
   MISC CONTAINERS
   ================================================================ */
#inhalt {
  background-color: var(--hu-light);
  margin-top: 5px;
  margin-bottom: 10px;
  padding-left: 7px;
  font-size: 11px;
  color: var(--hu-blue);
  clear: both;
}
#inhalt a { color: var(--hu-blue); font-size: 12px; }

#imprint   { float: right; width: 100px; }
#webmaster { float: left; width: 300px; }
#footer p, #footer a { font-size: 11px; }

.floatl { float: left; }
.floatr { float: right; }

/* ================================================================
   CONTACT PAGE
   ================================================================ */
.contact-info-box {
  background: var(--hu-light);
  border-left: 4px solid var(--hu-blue);
  padding: 0.7rem 1.1rem;
  margin-bottom: var(--space-lg);
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(240px, 100%), 240px));
  gap: 1.2rem;
  margin: var(--space-md) 0 var(--space-lg);
  justify-content: start;
}

.contact-card {
  border: 1px solid var(--hu-border);
  border-top: 4px solid var(--hu-blue);
  border-radius: var(--radius);
  padding: var(--space-md) 1.1rem 0.9rem;
  background: var(--hu-white);
}

.contact-card h3 {
  margin: 0 0 0.6rem 0;
  font-size: 1rem;
  color: var(--hu-blue);
}

.contact-card p {
  margin: 0.2rem 0;
}

.contact-email-link {
  display: inline-block;
  background: var(--hu-blue);
  color: var(--hu-white);
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  font-size: 0.875rem;
  text-decoration: none;
  margin-top: var(--space-sm);
  transition: background 0.2s;
}

.contact-email-link:visited {
  color: var(--hu-white);
}

.contact-email-link:hover {
  background: var(--hu-blue-dark);
  color: var(--hu-white);
  text-decoration: none;
}

/* ================================================================
   TABLES
   ================================================================ */
table { border: none; text-align: left; }
td { padding-left: 5px; padding-right: 5px; }
td.titel { font-weight: bold; }

table.alternierend tr:nth-child(even) { background-color: var(--hu-light); }
table.alternierend a:hover { background-color: transparent; }

table.pool-table { width: auto; }
table.pool-table th { padding: 0.4rem 1rem 0.4rem 0.5rem; text-align: left; }

table.rahmen td { border-top: 1px solid; border-right: 1px solid; }
table.rahmen td.titel { border-top: none; border-right: 1px solid; }
table.rahmen td.rechts { border-top: 1px solid; border-right: none; }
table.rahmen td.titelrechts { border-top: none; border-right: none; font-weight: bold; }

/* ================================================================
   LISTS
   ================================================================ */
li { margin-top: 0.2em; }
ul.nospace li { margin-top: 0; }
ul.spacious li { margin-top: 1em; }

/* ================================================================
   COMMAND / COMPARISON TABLES (.cmd-table)
   ================================================================ */
.cmd-table {
  width: auto;
  margin-top: 0.8rem;
  border-collapse: collapse;
}

.cmd-table th {
  padding: 0.4rem 1.2rem 0.4rem 0.5rem;
  text-align: left;
  background: var(--hu-light);
  font-weight: bold;
  border-bottom: 2px solid var(--hu-border);
}

.cmd-table td {
  padding: 0.35rem 1.2rem 0.35rem 0.5rem;
  vertical-align: top;
}

/* ================================================================
   SCREENSHOTS / FIGURES
   ================================================================ */
figure.screenshot {
  margin: 0;
  display: flex;
  flex-direction: column;
}

figure.screenshot img {
  border: 1px solid var(--hu-border);
  border-radius: var(--radius);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
  max-width: 100%;
  width: 100%;
  display: block;
}

figure.screenshot figcaption {
  font-size: 0.75rem;
  color: #555;
  margin-top: 0.35rem;
  line-height: 1.35;
}

/* Schrittweise Screenshots (z. B. Drucker-Einrichtung) */
.screenshot-steps {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(260px, 100%), 320px));
  gap: 1.2rem;
  margin: var(--space-md) 0 var(--space-lg);
  align-items: start;
  counter-reset: step-counter;
}

.screenshot-steps figure.screenshot {
  counter-increment: step-counter;
}

.screenshot-steps figure.screenshot figcaption::before {
  content: "Schritt " counter(step-counter) ": ";
  font-weight: bold;
  color: var(--hu-blue);
}

.screenshot-steps.steps-en figure.screenshot figcaption::before {
  content: "Step " counter(step-counter) ": ";
}

/* ================================================================
   GRAPH GRID (home.php)
   ================================================================ */
.graph-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: var(--space-xl);
}

.graph-tile {
  border: 1px solid var(--hu-border);
  padding: var(--space-md);
  border-radius: var(--radius);
  background: var(--hu-bg);
}

.graph-tile h4 {
  margin-top: 0;
  font-size: 1rem;
  color: var(--hu-blue);
}

.graph-tile img {
  width: 100%;
  height: auto;
  display: block;
}

.graph-tile h5 {
  margin-bottom: 0;
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.75rem;
  color: #555;
  font-weight: normal;
  word-break: break-all;
}

/* ================================================================
   LEGAL DOCUMENTS / BENUTZUNGSORDNUNG
   ================================================================ */
.legal-intro {
  background: var(--hu-light);
  border-left: 4px solid var(--hu-blue);
  padding: 0.8rem 1.1rem;
  margin: 0.5rem 0 var(--space-lg);
}

.legal-toc {
  background: var(--hu-bg);
  border: 1px solid var(--hu-border);
  border-radius: var(--radius);
  padding: 0.9rem 1.2rem 0.9rem 1rem;
  margin: 0 0 var(--space-xl);
  display: inline-block;
  min-width: 260px;
}

.legal-toc p {
  margin: 0 0 0.4rem;
  font-weight: bold;
  color: var(--hu-blue);
}

.legal-toc ol {
  margin: 0;
  padding-left: 1.4rem;
}

.legal-toc li {
  margin-top: 0.2rem;
}

.legal-section {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--hu-border);
}

.legal-section:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.legal-section h2 {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-top: 0;
}

.legal-badge {
  display: inline-block;
  background: var(--hu-blue);
  color: var(--hu-white);
  font-size: 0.75rem;
  font-weight: bold;
  padding: 0.1rem 0.45rem;
  border-radius: 3px;
  flex-shrink: 0;
  white-space: nowrap;
  font-family: "Verdana", sans-serif;
}

.legal-note {
  font-size: 0.82rem;
  color: #555;
  font-style: italic;
  margin: 0 0 var(--space-lg);
  padding: 0.5rem 0.8rem;
  border: 1px solid var(--hu-border);
  border-radius: 3px;
  background: #fafaf8;
}

/* ================================================================
   PASSWORD RULES (password-info.php)
   ================================================================ */
.pw-rules-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
  margin: var(--space-md) 0;
}

.pw-rules-section {
  background: var(--hu-white);
  border: 1px solid var(--hu-border);
  border-radius: var(--radius);
  padding: 0.85rem 1rem 0.75rem;
}

.pw-rules-section h3 {
  margin: 0 0 0.55rem;
  font-size: 0.95rem;
}

.pw-rules-section ul {
  margin: 0;
  padding-left: 0;
  list-style: none;
}

.pw-rules-section ul li {
  padding-left: 1.4em;
  position: relative;
  margin-top: 0.3em;
}

.pw-rules-section ul li::before {
  position: absolute;
  left: 0;
  font-size: 0.82rem;
  line-height: 1.6;
}

/* Grüne Häkchen für Anforderungen */
.pw-rules-required {
  border-top: 3px solid #2e7d32;
}

.pw-rules-required h3 {
  color: #2e7d32;
}

.pw-rules-required ul li::before {
  content: "✔";
  color: #2e7d32;
}

/* Amber-Kreuze für Verbote */
.pw-rules-forbidden {
  border-top: 3px solid #e6a800;
}

.pw-rules-forbidden h3 {
  color: #9a6e00;
}

.pw-rules-forbidden ul li::before {
  content: "✘";
  color: #c07a00;
}

/* Kleine Hinweis-Zeile unter den Karten */
.pw-rules-note {
  border-left: 3px solid var(--hu-border);
  padding: 0.3rem 0.9rem;
  margin: 0.5rem 0 var(--space-md);
}

.pw-rules-note ul {
  margin: 0;
  padding-left: 0;
  list-style: none;
}

.pw-rules-note ul li {
  padding-left: 1.4em;
  position: relative;
  margin-top: 0.25em;
  color: #444;
}

.pw-rules-note ul li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: #888;
  font-size: 0.82rem;
  line-height: 1.6;
}

/* ================================================================
   RESPONSIVE – Mobile (max 767px)
   ================================================================ */
@media (max-width: 767px) {
  .nav-toggle {
    display: block;
  }

  .main-nav {
    display: none;
  }

  .main-nav.open {
    display: block;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
  }

  .main-nav > ul {
    flex-direction: column;
  }

  .main-nav > ul > li > a {
    white-space: normal;
    padding: 0.7rem 1rem;
    border-bottom: 1px solid var(--hu-border);
  }

  /* Mobile dropdown: inline below parent */
  .nav-dropdown {
    position: static;
    display: none;
    box-shadow: none;
    border: none;
    border-top: 1px solid var(--hu-border);
    background: var(--hu-bg);
    min-width: 0;
  }

  .nav-item.open .nav-dropdown {
    display: block;
  }

  .nav-dropdown li a {
    color: var(--hu-blue);
    padding: 0.5rem 1.5rem;
    border-bottom: 1px solid var(--hu-border);
    font-size: 0.85rem;
  }

  .nav-dropdown li a:hover {
    background: var(--hu-light);
    color: var(--hu-blue);
  }

  .nav-dropdown li.active-sub > a {
    background: var(--hu-light);
    color: var(--hu-blue);
    font-weight: bold;
  }

  .logo-link img {
    height: 55px;
  }

  .header-institute {
    display: none;
  }

  .graph-grid {
    grid-template-columns: 1fr;
  }

  .icon-card-grid {
    grid-template-columns: 1fr 1fr;
  }

  .support-grid {
    grid-template-columns: 1fr;
  }

  .pw-rules-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    margin: -0.8rem -1.2rem var(--space-lg);
    padding: var(--space-lg) var(--space-md);
  }

  .hero h1 {
    font-size: 1.3rem;
  }
}

/* ================================================================
   RESPONSIVE – Desktop (min 768px)
   ================================================================ */
@media (min-width: 768px) {
  .nav-toggle {
    display: none;
  }

  .main-nav {
    display: block !important;
  }
}