:root {
  /* Core UI Palette (Light Mode Default) */
  --ink: #1c1c1c;
  --line: #343434;
  --paper: #ffffff;
  --bg-page: #f2f2f2;
  --bg-muted: #fafafa;
  --bg-weekend: #eae6df;      /* BD Weekend (Friday & Saturday) header tint */
  --text-muted: #737373;
  --hover-bar: #e7e7e7;
  --bar-bg: #f1f1f1;

  /* Weekday & Today Calendar Accents */
  --weekday-weekend-bg: #1c1c1c;
  --weekday-weekend-color: #ffffff;
  --today-header-bg: #fdfdfd;
  --today-badge-bg: #1c1c1c;
  --today-badge-color: #ffffff;

  /* Textures & Visual Accents */
  --texture-line: rgba(0, 0, 0, 0.17);
  --burst-ray-1: rgba(28, 28, 28, 0.09);
  --burst-ray-2: rgba(28, 28, 28, 0.065);
  --brand-wordmark-color: #001c4f;

  /* Event Categories (Pastel Tint Backgrounds) */
  --ctf: #fff0ee;             /* Cybersecurity / CTF (Soft Coral Red) */
  --hackathon: #f1fbea;       /* Hackathons / Build Sprints (Soft Mint Green) */
  --datathon: #fff6dc;        /* Data Science / ML (Warm Amber Yellow) */
  --cp: #f0ebfc;              /* ICPC / IUPC / NCPC Competitive Programming (Soft Lavender Violet) */
  --business-case: #faecd8;   /* Business Case Competitions (Distinct Warm Apricot Peach) */
  --fest: #fcebf5;            /* University & Technology Festivals (Soft Festival Pink) */
  --other: #eef4ff;           /* Workshops, Meetups, Tech Socials & Others (Soft Periwinkle Blue) */

  /* Layout Dimensions */
  --calendar-max-width: 1380px;
  --border-width: 1.5px;
  --border-thin: 1px;
  --day-cell-height: 170px;
  --day-header-height: 38px;
  --more-bar-height: 18px;
}

/* ── System Dark Mode Preference (when no explicit user override is set) ─ */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    /* Pure deep black & crunchy neo-brutalist dark mode */
    --ink: #ffffff;
    --line: #4a4a52;
    --paper: #0c0c0e;
    --bg-page: #000000;
    --bg-muted: #16161a;
    --bg-weekend: #141418;
    --text-muted: #a1a1aa;
    --hover-bar: #1c1c22;
    --bar-bg: #141418;
    --brand-wordmark-color: #ffffff;

    /* Calendar Weekdays & Today (Crunchy accents, no blinding white) */
    --weekday-weekend-bg: #18181c;
    --weekday-weekend-color: #f87171;
    --today-header-bg: #141418;
    --today-badge-bg: #e11d48;
    --today-badge-color: #ffffff;

    --texture-line: rgba(255, 255, 255, 0.09);
    --burst-ray-1: rgba(255, 255, 255, 0.06);
    --burst-ray-2: rgba(255, 255, 255, 0.038);

    /* Deep, crunchy, punchy category tones */
    --ctf: #3a1010;
    --hackathon: #0b3318;
    --datathon: #3d2b05;
    --cp: #29124a;
    --business-case: #381d09;
    --fest: #3b0f32;
    --other: #0e274a;
  }
}

/* ── Explicit User Override via [data-theme="dark"] ────────────────────── */
[data-theme="dark"] {
  /* Pure deep black & crunchy neo-brutalist dark mode */
  --ink: #ffffff;
  --line: #4a4a52;
  --paper: #0c0c0e;
  --bg-page: #000000;
  --bg-muted: #16161a;
  --bg-weekend: #141418;
  --text-muted: #a1a1aa;
  --hover-bar: #1c1c22;
  --bar-bg: #141418;
  --brand-wordmark-color: #ffffff;

  /* Calendar Weekdays & Today (Crunchy accents, no blinding white) */
  --weekday-weekend-bg: #18181c;
  --weekday-weekend-color: #f87171;
  --today-header-bg: #141418;
  --today-badge-bg: #e11d48;
  --today-badge-color: #ffffff;

  --texture-line: rgba(255, 255, 255, 0.09);
  --burst-ray-1: rgba(255, 255, 255, 0.06);
  --burst-ray-2: rgba(255, 255, 255, 0.038);

  /* Deep, crunchy, punchy category tones */
  --ctf: #3a1010;
  --hackathon: #0b3318;
  --datathon: #3d2b05;
  --cp: #29124a;
  --business-case: #381d09;
  --fest: #3b0f32;
  --other: #0e274a;
}