/* =============================================================
   CodeForge — Global Design System
   base.css | Single source of truth for all design tokens,
   resets, shared components, and keyframes.
   Loaded once via base.html → inherited by every page.
   ============================================================= */

/* ─────────────────────────────────────────────────────────────
   1. DESIGN TOKENS  (CSS Custom Properties)
   All colour, spacing, radius, shadow and transition values
   live here. Pages NEVER redefine these.
   ───────────────────────────────────────────────────────────── */
:root {
    /* Warm Mesh Theme (Default Global) */
    --bg-primary:    #f5efe6;
    --bg-secondary:  #ede8df;
    --bg-elevated:   #ffffff;
    --bg-card:       rgba(255, 255, 255, 0.72);

    --text-primary:   #111111;
    --text-secondary: #444444;
    --text-muted:     #888888;

    --border:       #d6d0c7;
    --border-hover: #bcb6ae;

    --glass-bg:     rgba(255, 255, 255, 0.45);
    --glass-border: rgba(0, 0, 0, 0.08);

    --accent-primary:   #111111;
    --accent-secondary: #666666;
    --accent-gradient:  linear-gradient(135deg, #111111 0%, #444444 100%);

    --success: #00c851;
    --error:   #ff4444;
    --warning: #ffbb33;

    /* Shadows */
    --shadow-sm:  0 2px 8px  rgba(0, 0, 0, 0.06);
    --shadow-md:  0 8px 24px rgba(0, 0, 0, 0.09);
    --shadow-lg:  0 16px 40px rgba(0, 0, 0, 0.12);
    --shadow-glow: 0 0 20px rgba(0, 0, 0, 0.08);

    /* Spacing scale */
    --space-xs:  4px;
    --space-sm:  8px;
    --space-md:  16px;
    --space-lg:  24px;
    --space-xl:  32px;
    --space-2xl: 48px;
    --space-3xl: 64px;

    /* Border-radius scale */
    --radius:      8px;
    --radius-lg:   12px;
    --radius-xl:   16px;
    --radius-full: 9999px;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'SF Mono', Consolas, monospace;

    /* Transitions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ─────────────────────────────────────────────────────────────
   2. RESET & BASE
   ───────────────────────────────────────────────────────────── */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background:
        radial-gradient(ellipse at 0% 0%,   #b8d9f4 0%, transparent 50%),
        radial-gradient(ellipse at 100% 80%, #f5bf5a 0%, transparent 50%),
        radial-gradient(ellipse at 60% 100%, #f0c97e 0%, transparent 40%),
        var(--bg-primary);
    background-attachment: fixed;
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    transition: var(--transition);
}

/* ─────────────────────────────────────────────────────────────
   3. GLOBAL BUTTON SYSTEM
   ───────────────────────────────────────────────────────────── */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-lg);
    border: none;
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 0.875rem;
    font-family: inherit;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    white-space: nowrap;
}

.btn::before {
    content: '';
    position: absolute;
    inset: 0;
    left: -100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.5s ease;
}
.btn:hover::before { left: 100%; }

.btn-primary {
    background: var(--accent-gradient);
    color: #ffffff;
    box-shadow: var(--shadow-md);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.btn-secondary {
    background: var(--bg-elevated);
    color: var(--text-primary);
    border: 1px solid var(--border);
}
.btn-secondary:hover {
    background: var(--border-hover);
    border-color: #111111;
    transform: translateY(-1px);
}

.btn-danger {
    background: transparent;
    color: var(--error);
    border: 1px solid var(--error);
}
.btn-danger:hover {
    background: rgba(255, 68, 68, 0.1);
    transform: translateY(-1px);
}

/* ─────────────────────────────────────────────────────────────
   4. NAVBAR (Warm Mesh Style)
   ───────────────────────────────────────────────────────────── */
.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md) var(--space-lg);
    background: rgba(255, 255, 255, 0.4);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: var(--transition);
}

/* Brand / Logo */
.navbar-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.75rem;
    font-weight: 800;
    text-decoration: none;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    flex-shrink: 0;
}

/* Right side container */
.navbar-right {
    display: flex;
    align-items: center;
    gap: var(--space-2xl);
}

/* Nav links list */
.navbar-nav {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-link {
    display: inline-block;
    color: #555555;
    text-decoration: none;
    font-weight: 500;
    padding: var(--space-xs) 0;
    position: relative;
    transition: color 0.25s ease;
}

.nav-link:hover,
.nav-link.active {
    color: #111111;
}

/* Ultra-fine underline for active items */
.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: #111111;
    border-radius: 2px;
}

/* Right-side actions cluster */
.navbar-actions {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

/* Theme toggle button */
.theme-toggle {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    cursor: pointer;
    padding: var(--space-sm);
    border-radius: var(--radius);
    transition: var(--transition);
    font-size: 1.2rem;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.theme-toggle:hover {
    color: var(--text-primary);
    background: var(--border-hover);
    transform: scale(1.05);
}
.theme-toggle:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* Authenticated user avatar button */
.profile-dropdown { position: relative; }

.profile-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2px;
    border-radius: 50%;
    text-decoration: none;
    background: transparent;
    border: 2px solid transparent;
    transition: var(--transition);
}
.profile-btn:hover {
    border-color: rgba(0, 0, 0, 0.1);
    transform: scale(1.05);
}

.nav-logout-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 6px 16px;
    border-radius: 999px;
    text-decoration: none;
    color: #555555;
    background: transparent;
    border: 1px solid transparent;
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition);
}
.nav-logout-btn:hover {
    color: #111111;
    background: rgba(0, 0, 0, 0.05);
}

.nav-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: #111111;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    font-weight: 700;
    color: #ffffff;
    flex-shrink: 0;
}


/* ─────────────────────────────────────────────────────────────
   5. FOOTER
   ───────────────────────────────────────────────────────────── */
.footer {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    padding: var(--space-xl) var(--space-md);
    text-align: center;
    font-size: 0.875rem;
    border-top: 1px solid var(--border);
    margin-top: var(--space-3xl);
}

.footer p {
    margin: 0 0 var(--space-md);
    color: var(--text-muted);
    font-weight: 400;
}

.footer-links {
    list-style: none;
    padding: 0;
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
    flex-wrap: wrap;
}

.footer-links li a {
    color: var(--accent-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.25s ease;
}
.footer-links li a:hover { color: var(--accent-primary); }


/* ─────────────────────────────────────────────────────────────
   6. SHARED DIFFICULTY BADGES
   Used on home, allproblems, and problem_detail.
   ───────────────────────────────────────────────────────────── */
.difficulty-badge,
.difficulty {
    display: inline-block;
    padding: var(--space-xs) var(--space-md);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    white-space: nowrap;
    border: 1px solid transparent;
}

.difficulty-easy,
.difficulty.easy {
    background: transparent;
    color: var(--success);
    border-color: var(--success);
}

.difficulty-medium,
.difficulty.medium {
    background: transparent;
    color: var(--warning);
    border-color: var(--warning);
}

.difficulty-hard,
.difficulty.hard {
    background: transparent;
    color: var(--error);
    border-color: var(--error);
}


/* ─────────────────────────────────────────────────────────────
   7. SHARED VERDICT BADGES
   Used on home (recent submissions) and problem_detail.
   ───────────────────────────────────────────────────────────── */
.verdict {
    display: inline-block;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border: 1px solid transparent;
}
.verdict.accepted {
    background: transparent;
    color: var(--success);
    border-color: var(--success);
}
.verdict.wrong-answer {
    background: transparent;
    color: var(--error);
    border-color: var(--error);
}
.verdict.time-limit-exceeded {
    background: transparent;
    color: var(--warning);
    border-color: var(--warning);
}
.verdict.runtime-error {
    background: transparent;
    color: var(--accent-secondary);
    border-color: var(--accent-secondary);
}


/* ─────────────────────────────────────────────────────────────
   8. SHARED KEYFRAMES
   ───────────────────────────────────────────────────────────── */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to   { opacity: 1; transform: translateY(0);    }
}

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

@keyframes pulse {
    0%, 100% { opacity: 1;   }
    50%       { opacity: 0.5; }
}

@keyframes backgroundShift {
    0%, 100% { opacity: 1;   }
    50%       { opacity: 0.7; }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Utility animation classes */
.fade-in-up { animation: fadeInUp 0.6s ease-out forwards; }
.pulse      { animation: pulse 2s infinite; }


/* ─────────────────────────────────────────────────────────────
   9. GLOBAL UTILITIES
   ───────────────────────────────────────────────────────────── */
.sr-only {
    position: absolute;
    width: 1px; height: 1px;
    padding: 0; margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    border: 0;
}

.text-accent   { color: var(--accent-primary); }
.text-muted    { color: var(--text-muted); }
.text-success  { color: var(--success); }
.text-error    { color: var(--error); }
.text-warning  { color: var(--warning); }
.font-mono     { font-family: var(--font-mono); }

.card {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    transition: var(--transition);
}
.card:hover {
    border-color: var(--border-hover);
    box-shadow: var(--shadow-md);
}


/* ─────────────────────────────────────────────────────────────
   10. RESPONSIVE — Navbar collapses on mobile
   ───────────────────────────────────────────────────────────── */
@media (max-width: 768px) {
    .navbar {
        padding: var(--space-md);
        flex-wrap: wrap;
        gap: var(--space-sm);
    }

    .navbar-nav {
        gap: var(--space-md);
    }

    .profile-name {
        display: none; /* show avatar only on small screens */
    }

    .profile-btn {
        padding: var(--space-sm);
    }

    .navbar-actions {
        gap: var(--space-sm);
    }
}

@media (max-width: 480px) {
    .navbar-nav {
        display: none; /* hamburger menu territory — hidden for now */
    }
}

/* ─────────────────────────────────────────────────────────────
   11. AUTH TOGGLE CAPSULE (Navbar Login/Register toggle)
   ───────────────────────────────────────────────────────────── */
.auth-toggle-capsule {
    display: flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.06);
    border-radius: 999px;
    padding: 3px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

body.home-mesh-background .auth-toggle-capsule {
    background: rgba(0, 0, 0, 0.05);
    border: 1px solid rgba(0, 0, 0, 0.03);
}

.auth-toggle-btn {
    padding: 6px 18px;
    border-radius: 999px;
    font-size: 0.875rem;
    font-weight: 600;
    text-decoration: none;
    transition: background-color 0.25s cubic-bezier(0.4, 0, 0.2, 1), color 0.25s ease;
    white-space: nowrap;
    text-align: center;
    line-height: 1.4;
    color: #b3b3b3;
}

.auth-toggle-btn:hover {
    color: #ffffff;
}

.auth-toggle-btn.active {
    background: #ffffff;
    color: #0a0a0f;
    box-shadow: 0 2px 8px rgba(255, 255, 255, 0.1);
}

body.home-mesh-background .auth-toggle-btn {
    color: #444444;
}

body.home-mesh-background .auth-toggle-btn:hover {
    color: #111111;
}

body.home-mesh-background .auth-toggle-btn.active {
    background: #111111;
    color: #ffffff;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}