/* css/base.css */

/* ------------------------- */
/* --- CSS Variables --- */
/* ------------------------- */
:root {
    --font-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-secondary: 'Roboto', sans-serif;

    /* Light Theme (Default) */
    --bg-primary-light: #ffffff;
    --bg-secondary-light: #f8f9fa;
    --bg-tertiary-light: #e9ecef;
    --bg-interactive-light: #f0f4f8;
    --text-primary-light: #212529;
    --text-secondary-light: #495057;
    --text-muted-light: #6c757d;
    --accent-primary-light: #007bff;
    --accent-primary-rgb-light: 0, 123, 255;
    --accent-secondary-light: #0056b3;
    --border-color-light: #dee2e6;
    --shadow-color-light: rgba(0, 0, 0, 0.05);
    --shadow-strong-light: rgba(0, 0, 0, 0.1);
    --success-light: #28a745;
    --success-rgb-light: 40, 167, 69;
    --warning-light: #ffc107;
    --warning-rgb-light: 255, 193, 7;
    --danger-light: #dc3545;
    --danger-rgb-light: 220, 53, 69;
    --info-light: #17a2b8;
    --info-rgb-light: 23, 162, 184;
    --revising-light: #ffda69; /* Yellowish */

    /* Dark Theme Variables */
    --bg-primary-dark: #1e2027;
    --bg-secondary-dark: #2a2d35;
    --bg-tertiary-dark: #363942;
    --bg-interactive-dark: #30333a;
    --text-primary-dark: #f8f9fa;
    --text-secondary-dark: #adb5bd;
    --text-muted-dark: #868e96;
    --accent-primary-dark: #00a2ff;
    --accent-primary-rgb-dark: 0, 162, 255;
    --accent-secondary-dark: #007acc;
    --border-color-dark: #495057;
    --shadow-color-dark: rgba(255, 255, 255, 0.03);
    --shadow-strong-dark: rgba(255, 255, 255, 0.07);
    --success-dark: #32c85a;
    --success-rgb-dark: 50, 200, 90; /* Example, adjust */
    --warning-dark: #fd7e14;
    --warning-rgb-dark: 253, 126, 20; /* Example, adjust */
    --danger-dark: #f25566;
    --danger-rgb-dark: 242, 85, 102; /* Example, adjust */
    --info-dark: #28b8d0;
    --info-rgb-dark: 40, 184, 208; /* Example, adjust */
    --revising-dark: #ffda69; /* Can be same or adjusted for dark */

    /* Default to Light Theme Variables */
    --bg-primary: var(--bg-primary-light);
    --bg-secondary: var(--bg-secondary-light);
    --bg-tertiary: var(--bg-tertiary-light);
    --bg-interactive: var(--bg-interactive-light);
    --text-primary: var(--text-primary-light);
    --text-secondary: var(--text-secondary-light);
    --text-muted: var(--text-muted-light);
    --accent-primary: var(--accent-primary-light);
    --accent-primary-rgb: var(--accent-primary-rgb-light);
    --accent-secondary: var(--accent-secondary-light);
    --border-color: var(--border-color-light);
    --shadow-color: var(--shadow-color-light);
    --shadow-strong: var(--shadow-strong-light);

    --success: var(--success-light);
    --success-rgb: var(--success-rgb-light);
    --warning: var(--warning-light);
    --warning-rgb: var(--warning-rgb-light);
    --danger: var(--danger-light);
    --danger-rgb: var(--danger-rgb-light);
    --info: var(--info-light);
    --info-rgb: var(--info-rgb-light);
    --revising: var(--revising-light);
    /* --revising-rgb would also be needed if using rgba for revising background */

    /* Status Semantic Colors (can be overridden by theme) */
    --status-todo-bg: var(--bg-tertiary);
    --status-todo-text: var(--text-muted);
    --status-revising-bg: rgba(var(--warning-rgb), 0.55); /* Use revising color */
    --status-revising-text: var(--warning);
    --status-learned-bg: rgba(var(--success-rgb), 0.55);
    --status-learned-text: var(--success);
    --status-need-help-bg: rgba(var(--danger-rgb), 0.55);
    --status-need-help-text: var(--danger);

    /* Layout Dimensions & Defaults */
    --sidebar-width: 10vw; /* Default for desktop */
    --sidebar-width-mobile: 0px; /* Example: sidebar collapsed on mobile */
    --topbar-height: 8vh;
    --border-radius-sm: 0.2vh;
    --border-radius-md: 0.2vh;
    --border-radius-lg: 0.3vh;
    --transition-speed-fast: 0.25s;
    --transition-speed-normal: 0.4s;
    --transition-speed-slow: 0.6s;
}

body[data-theme="dark"] {
    --bg-primary: var(--bg-primary-dark);
    --bg-secondary: var(--bg-secondary-dark);
    --bg-tertiary: var(--bg-tertiary-dark);
    --bg-interactive: var(--bg-interactive-dark);
    --text-primary: var(--text-primary-dark);
    --text-secondary: var(--text-secondary-dark);
    --text-muted: var(--text-muted-dark);
    --accent-primary: var(--accent-primary-dark);
    --accent-primary-rgb: var(--accent-primary-rgb-dark);
    --accent-secondary: var(--accent-secondary-dark);
    --border-color: var(--border-color-dark);
    --shadow-color: var(--shadow-color-dark);
    --shadow-strong: var(--shadow-strong-dark);
    --success: var(--success-dark);
    --success-rgb: var(--success-rgb-dark);
    --warning: var(--warning-dark);
    --warning-rgb: var(--warning-rgb-dark);
    --danger: var(--danger-dark);
    --danger-rgb: var(--danger-rgb-dark);
    --info: var(--info-dark);
    --info-rgb: var(--info-rgb-dark);
    --revising: var(--revising-dark);

    --status-todo-bg: var(--bg-tertiary-dark);
    --status-todo-text: var(--text-muted-dark);
    /* Revising, Learned, Need Help backgrounds will use their respective rgb vars for dark theme */
}

/* ------------------------- */
/* --- Base Styles --- */
/* ------------------------- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 0.8rem; /* Base font size */
    /* If body overflow:hidden is kept, prevent horizontal scroll on html too */
    /* overflow-x: hidden;  */
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    transition: background-color var(--transition-speed-normal) ease, color var(--transition-speed-normal) ease;
    overflow: hidden; /* CAUTION: This prevents body scrolling. Ensure your app has internal scrolling regions if needed. */
    /* If you want the body to scroll vertically but not horizontally: */
    /* overflow-y: auto; */
    /* overflow-x: hidden; */
}

a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color var(--transition-speed-fast) ease;
}
a:hover {
    color: var(--accent-secondary);
    text-decoration: underline;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-secondary);
    color: var(--text-primary);
    margin-bottom: 0.75em;
    line-height: 1.3;
    font-weight: 600;
}
h1 { font-size: 2rem; }
h2 { font-size: 1.6rem; }
h3 { font-size: 1.3rem; }
h4 { font-size: 1.1rem; }
h5 { font-size: 1rem; }
h6 { font-size: 0.9rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

ul, ol {
    list-style: none; /* Reset globally, specific lists can re-add */
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* Basic form row structure */
.form-row {
    display: flex;
    flex-wrap: wrap;
    margin-right: -5px;
    margin-left: -5px;
}
.form-row > [class*="col-"] { /* Generic column padding */
    padding-right: 5px;
    padding-left: 5px;
    margin-bottom: 1rem;
    width: 100%; /* Default to full width, overridden by col-* classes */
}
/* Desktop column widths */
.col-md-7 { flex: 0 0 58.333333%; max-width: 58.333333%; }
.col-md-5 { flex: 0 0 41.666667%; max-width: 41.666667%; }
.col-md-4 { flex: 0 0 33.333333%; max-width: 33.333333%; }
.col-md-3 { flex: 0 0 25%; }
/* Add more .col-md-* as needed or other breakpoints like .col-lg-* */

/* Basic list group styling */
.list-group {
    padding-left: 0;
    margin-bottom: 0;
}
.list-group-item {
    position: relative;
    display: block;
    padding: .75rem 1.25rem;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
}
.list-group-item:first-child { border-top-left-radius: var(--border-radius-md); border-top-right-radius: var(--border-radius-md); }
.list-group-item:last-child { border-bottom-right-radius: var(--border-radius-md); border-bottom-left-radius: var(--border-radius-md); margin-bottom: 0; border-bottom-width: 1px; }
.list-group-item + .list-group-item { border-top-width: 0; }
.list-group-flush .list-group-item { border-right-width: 0; border-left-width: 0; border-radius: 0; }
.list-group-flush .list-group-item:last-child { border-bottom-width: 0; }


/* Utility classes */
.text-center { text-align: center !important; }
.text-muted { color: var(--text-muted) !important; }
.text-success { color: var(--success) !important; }
.text-danger { color: var(--danger) !important; }
.text-warning { color: var(--warning) !important; }
.text-info { color: var(--info) !important; }
.text-primary { color: var(--accent-primary) !important; }

.d-block { display: block !important; }
.d-flex { display: flex !important; }
.justify-content-between { justify-content: space-between !important; }
.align-items-center { align-items: center !important; }
.align-self-end { align-self: flex-end !important; }

.mt-1 { margin-top: 0.25rem !important; }
.mt-2 { margin-top: 0.5rem !important; }
.mt-3 { margin-top: 1rem !important; }
.mt-4 { margin-top: 1.5rem !important; }
.mb-1 { margin-bottom: 0.25rem !important; }
.mb-2 { margin-bottom: 0.5rem !important; }
.mb-3 { margin-bottom: 1rem !important; }
.mr-1 { margin-right: 0.25rem !important; }
.mr-2 { margin-right: 0.5rem !important; }
.p-3 { padding: 1rem !important; }

.sr-only {
    position: absolute; width: 1px; height: 1px; padding: 0;
    margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0);
    white-space: nowrap; border: 0;
}
.fade-in {
    animation: fadeIn var(--transition-speed-normal) ease-out forwards;
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.spinner {
    display: inline-block;
    width: 1.2em;
    height: 1.2em;
    border: 3px solid rgba(var(--accent-primary-rgb),0.3);
    border-radius: 50%;
    border-top-color: var(--accent-primary);
    animation: spin 0.8s linear infinite;
    vertical-align: middle;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Dark Mode Toggle Button */
#darkModeToggle {
    position: relative;
    width: 2.5rem;
    height: 2.5rem;
    border: none;
    border-radius: 50%;
    background-color: var(--bg-interactive);
    color: var(--text-primary);
    cursor: pointer;
    font-size: 1.2rem;
    transition: all var(--transition-speed-fast) ease;
    box-shadow: 0 2px 8px var(--shadow-color);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

#darkModeToggle:hover {
    transform: translateY(-2px) scale(1.05);
    box-shadow: 0 4px 12px var(--shadow-strong);
    background-color: var(--bg-tertiary);
}

#darkModeToggle:active {
    transform: translateY(1px) scale(0.95);
}

#darkModeToggle::before {
    content: "";
    position: absolute;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at center,
    var(--accent-primary) 0%,
    transparent 70%);
    opacity: 0;
    transition: opacity var(--transition-speed-fast) ease;
}

#darkModeToggle:hover::before {
    opacity: 0.2;
}

/* Custom Scrollbar Styles (Primarily for Desktop) */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
    background-color: var(--bg-tertiary);
}
::-webkit-scrollbar-thumb {
    background-color: var(--text-muted);
    border-radius: 4px;
    border: 2px solid var(--bg-tertiary);
}
::-webkit-scrollbar-thumb:hover {
    background-color: var(--text-secondary);
}
::-webkit-scrollbar-track-piece {
  /* background-color: var(--bg-tertiary); */
}
::-webkit-scrollbar-button { display: none; }