/* ============================================
   BASE.CSS
   Reset, CSS Variables, Typography
   ============================================ */

@font-face {
    font-family: 'Hind Siliguri';
    src: url('../assets/fonts/HindSiliguri-Light.ttf') format('truetype');
    font-weight: 300;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Hind Siliguri';
    src: url('../assets/fonts/HindSiliguri-Regular.ttf') format('truetype');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Hind Siliguri';
    src: url('../assets/fonts/HindSiliguri-Medium.ttf') format('truetype');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Hind Siliguri';
    src: url('../assets/fonts/HindSiliguri-SemiBold.ttf') format('truetype');
    font-weight: 600;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Hind Siliguri';
    src: url('../assets/fonts/HindSiliguri-Bold.ttf') format('truetype');
    font-weight: 700;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Li Shamim Cholontika';
    src: url('../assets/fonts/LiShamimCholontikaUnicode-Regular.ttf') format('truetype');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

/* ============================================
   CSS Reset
   ============================================ */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    min-height: 100vh;
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img,
picture,
video,
canvas,
svg {
    display: block;
    max-width: 100%;
    height: auto;
}

input,
button,
textarea,
select {
    font: inherit;
}

ul,
ol {
    list-style: none;
}

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

button {
    cursor: pointer;
    border: none;
    background: none;
}

/* Remove default button styles */
button:focus,
input:focus,
textarea:focus,
select:focus {
    outline: none;
}

/* ============================================
   CSS Variables - Base Values
   ============================================ */
:root {
    /* Font Family */
    --font-primary: 'Hind Siliguri', 'Noto Sans Bengali', sans-serif;
    --font-display: 'Hind Siliguri', sans-serif;
    
    /* Font Sizes */
    --fs-xs: 0.75rem;      /* 12px */
    --fs-sm: 0.875rem;     /* 14px */
    --fs-base: 1rem;       /* 16px */
    --fs-md: 1.125rem;     /* 18px */
    --fs-lg: 1.25rem;      /* 20px */
    --fs-xl: 1.5rem;       /* 24px */
    --fs-2xl: 1.875rem;    /* 30px */
    --fs-3xl: 2.25rem;     /* 36px */
    --fs-4xl: 3rem;        /* 48px */
    --fs-5xl: 3.75rem;     /* 60px */
    
    /* Font Weights */
    --fw-light: 300;
    --fw-regular: 400;
    --fw-medium: 500;
    --fw-semibold: 600;
    --fw-bold: 700;
    
    /* Line Heights */
    --lh-tight: 1.2;
    --lh-normal: 1.5;
    --lh-relaxed: 1.7;
    --lh-loose: 2;
    
    /* Spacing Scale */
    --space-1: 0.25rem;    /* 4px */
    --space-2: 0.5rem;     /* 8px */
    --space-3: 0.75rem;    /* 12px */
    --space-4: 1rem;       /* 16px */
    --space-5: 1.25rem;    /* 20px */
    --space-6: 1.5rem;     /* 24px */
    --space-8: 2rem;       /* 32px */
    --space-10: 2.5rem;    /* 40px */
    --space-12: 3rem;      /* 48px */
    --space-16: 4rem;      /* 64px */
    --space-20: 5rem;      /* 80px */
    --space-24: 6rem;      /* 96px */
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-2xl: 32px;
    --radius-full: 9999px;
    
    /* Shadows - Base */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.25);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    --transition-bounce: 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    
    /* Z-Index Scale */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal-backdrop: 400;
    --z-modal: 500;
    --z-popover: 600;
    --z-tooltip: 700;
    --z-notification: 800;
    
    /* Container Widths */
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;
    --container-2xl: 1536px;
    
    /* Navbar Height */
    --navbar-height: 70px;
    --navbar-height-mobile: 60px;
}

/* ============================================
   Typography Base Styles
   ============================================ */
body {
    font-family: var(--font-primary);
    font-size: var(--fs-base);
    font-weight: var(--fw-regular);
    line-height: var(--lh-relaxed);
}

/* Headings */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: var(--fw-bold);
    line-height: var(--lh-tight);
    margin-bottom: var(--space-4);
}

h1 {
    font-size: clamp(var(--fs-2xl), 5vw, var(--fs-5xl));
}

h2 {
    font-size: clamp(var(--fs-xl), 4vw, var(--fs-3xl));
}

h3 {
    font-size: clamp(var(--fs-lg), 3vw, var(--fs-2xl));
}

h4 {
    font-size: var(--fs-xl);
}

h5 {
    font-size: var(--fs-lg);
}

h6 {
    font-size: var(--fs-md);
}

/* Paragraphs */
p {
    font-size: var(--fs-base);
    line-height: var(--lh-relaxed);
    margin-bottom: var(--space-4);
}

p:last-child {
    margin-bottom: 0;
}

/* Small Text */
small {
    font-size: var(--fs-sm);
}

/* Strong & Bold */
strong, b {
    font-weight: var(--fw-semibold);
}

/* Emphasis & Italic */
em, i {
    font-style: italic;
}

/* Links Base */
a {
    transition: color var(--transition-fast);
}

/* Selection */
::selection {
    background-color: var(--accent-primary);
    color: white;
}

/* Focus Visible for Accessibility */
:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* Screen Reader Only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* Text Utilities */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-uppercase { text-transform: uppercase; }
.text-lowercase { text-transform: lowercase; }
.text-capitalize { text-transform: capitalize; }

.text-truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.text-gradient {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}