/* ============================================
   ROOT VARIABLES
   ============================================ */
:root {
    --bg-primary: #f0f4f8;
    --bg-card: rgba(255, 255, 255, 0.75);
    --bg-card-solid: #ffffff;
    --bg-input: rgba(255, 255, 255, 0.5);
    --text-primary: #0b1120;
    --text-secondary: #4a5a72;
    --text-muted: #8a9bb0;
    --border-color: rgba(255, 255, 255, 0.25);
    --shadow-sm: 0 8px 32px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 12px 48px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.08);
    --shadow-glass: 0 8px 32px rgba(0, 0, 0, 0.06);
    --gradient-start: #fbbf24;
    --gradient-end: #f59e0b;
    --tab-active: #f59e0b;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    --transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    --radius-card: 28px;
    --radius-btn: 16px;
    --glass-blur: 20px;
    --font: 'Inter', 'Segoe UI', system-ui, sans-serif;
}

[data-theme="dark"] {
    --bg-primary: #0a0f1e;
    --bg-card: rgba(20, 30, 50, 0.7);
    --bg-card-solid: #141e32;
    --bg-input: rgba(30, 45, 70, 0.6);
    --text-primary: #eef2f8;
    --text-secondary: #a0b4cc;
    --text-muted: #5a6f8a;
    --border-color: rgba(255, 255, 255, 0.08);
    --shadow-sm: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 12px 48px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.5);
    --shadow-glass: 0 8px 32px rgba(0, 0, 0, 0.35);
}

/* ============================================
   RESET & BASE
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font);
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: var(--transition);
    min-height: 100vh;
    padding: 24px;
    background-image:
        radial-gradient(ellipse at 10% 20%, rgba(245, 158, 11, 0.05) 0%, transparent 60%),
        radial-gradient(ellipse at 90% 80%, rgba(59, 130, 246, 0.04) 0%, transparent 60%);
    background-attachment: fixed;
}

/* ============================================
   GLASS CARD
   ============================================ */
.glass-card {
    background: var(--bg-card);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--border-color);
    border-radius: var(--radius-card);
    box-shadow: var(--shadow-glass);
    transition: var(--transition);
}

.glass-card:hover {
    box-shadow: var(--shadow-md);
    border-color: rgba(245, 158, 11, 0.15);
}

/* ============================================
   CONTAINER
   ============================================ */
.calc-wrapper {
    max-width: 1100px;
    margin: 0 auto;
    animation: fadeSlideUp 0.7s ease both;
}

@keyframes fadeSlideUp {
    from {
        opacity: 0;
        transform: translateY(30px) scale(0.98);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* ============================================
   HEADER
   ============================================ */
.calc-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 28px;
    flex-wrap: wrap;
    gap: 16px;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 14px;
}

.back-home {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    padding: 10px 18px;
    border-radius: 50px;
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.back-home:hover {
    color: var(--tab-active);
    transform: translateX(-4px);
    border-color: var(--tab-active);
    box-shadow: var(--shadow-sm);
}

.calc-title {
    font-size: 2rem;
    font-weight: 900;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    display: flex;
    align-items: center;
    gap: 12px;
}

.calc-title i {
    background: none;
    -webkit-background-clip: unset;
    background-clip: unset;
    color: var(--tab-active);
    font-size: 1.8rem;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.theme-toggle {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 46px;
    height: 46px;
    cursor: pointer;
    font-size: 1.2rem;
    color: var(--text-primary);
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background: var(--tab-active);
    color: white;
    transform: rotate(20deg) scale(1.05);
    border-color: var(--tab-active);
}

/* ============================================
   TABS (مشترک بین صفحات)
   ============================================ */
.calc-tabs {
    display: flex;
    gap: 6px;
    padding: 6px;
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border-radius: 60px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    margin-bottom: 28px;
    flex-wrap: wrap;
}

.calc-tab {
    flex: 1;
    min-width: 80px;
    background: transparent;
    border: none;
    padding: 12px 18px;
    border-radius: 40px;
    font-size: 0.82rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-family: var(--font);
    position: relative;
    text-decoration: none;
}

.calc-tab i {
    font-size: 1.1rem;
    transition: var(--transition);
}

.calc-tab:hover:not(.active) {
    background: var(--bg-input);
    color: var(--text-primary);
}

.calc-tab.active {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: #fff;
    box-shadow: 0 4px 20px rgba(245, 158, 11, 0.3);
    transform: scale(1.02);
}

.calc-tab.active i {
    color: #fff;
}

/* ============================================
   CARDS
   ============================================ */
.card {
    background: var(--bg-card);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--border-color);
    border-radius: var(--radius-card);
    padding: 28px 30px;
    box-shadow: var(--shadow-glass);
    transition: var(--transition);
    margin-bottom: 20px;
}

.card:hover {
    box-shadow: var(--shadow-md);
    border-color: rgba(245, 158, 11, 0.10);
}

.card-title {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 12px;
    letter-spacing: -0.01em;
}

.card-title i {
    color: var(--tab-active);
    font-size: 1.3rem;
}

/* ============================================
   FORM ELEMENTS
   ============================================ */
.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    font-weight: 600;
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-bottom: 6px;
    letter-spacing: 0.02em;
    text-transform: uppercase;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px;
}

.form-row-3 {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 14px;
}

@media (max-width: 600px) {
    .form-row {
        grid-template-columns: 1fr;
    }
    .form-row-3 {
        grid-template-columns: 1fr;
    }
}

input,
select {
    width: 100%;
    padding: 14px 18px;
    border-radius: 16px;
    border: 2px solid var(--border-color);
    background: var(--bg-input);
    backdrop-filter: blur(8px);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: var(--font);
    transition: var(--transition);
    outline: none;
    direction: ltr;
    text-align: left;
}

input:focus,
select:focus {
    border-color: var(--tab-active);
    box-shadow: 0 0 0 4px rgba(245, 158, 11, 0.08);
    background: var(--bg-card);
}

input::placeholder {
    color: var(--text-muted);
    font-weight: 400;
}

input[type="number"] {
    -moz-appearance: textfield;
}
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
    padding: 14px 28px;
    border-radius: var(--radius-btn);
    border: none;
    font-weight: 700;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-family: var(--font);
    letter-spacing: 0.01em;
}

.btn-primary {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: #fff;
    box-shadow: 0 4px 16px rgba(245, 158, 11, 0.2);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 32px rgba(245, 158, 11, 0.35);
}

.btn-secondary {
    background: var(--bg-input);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(8px);
}

.btn-secondary:hover {
    background: var(--bg-card);
    border-color: var(--tab-active);
    transform: translateY(-2px);
}

.btn-success {
    background: var(--success);
    color: #fff;
    box-shadow: 0 4px 16px rgba(16, 185, 129, 0.2);
}

.btn-success:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 32px rgba(16, 185, 129, 0.35);
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.78rem;
    border-radius: 12px;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

/* ============================================
   RESULT BOX
   ============================================ */
.result-box {
    background: var(--bg-input);
    backdrop-filter: blur(8px);
    border-radius: 18px;
    padding: 20px 24px;
    margin-top: 18px;
    border: 2px solid var(--border-color);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.result-box::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 4px;
    height: 100%;
    border-radius: 0 4px 4px 0;
    transition: var(--transition);
}

.result-box.success::before {
    background: var(--success);
}
.result-box.error::before {
    background: var(--error);
}
.result-box.warning::before {
    background: var(--warning);
}

.result-box.success {
    border-color: rgba(16, 185, 129, 0.2);
}
.result-box.error {
    border-color: rgba(239, 68, 68, 0.2);
}
.result-box.warning {
    border-color: rgba(245, 158, 11, 0.2);
}

.result-label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.result-value {
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--text-primary);
    direction: ltr;
    font-family: 'Inter', monospace;
    margin-top: 4px;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.result-value .highlight {
    color: var(--tab-active);
}
.result-value .positive {
    color: var(--success);
}
.result-value .negative {
    color: var(--error);
}

.result-sub {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 6px;
    line-height: 1.6;
}

.result-detail-row {
    display: flex;
    justify-content: space-between;
    padding: 6px 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.9rem;
}
.result-detail-row:last-child {
    border-bottom: none;
}
.result-detail-row .label {
    color: var(--text-secondary);
}
.result-detail-row .value {
    font-weight: 600;
    color: var(--text-primary);
}
.result-detail-row .value.final {
    font-size: 1.2rem;
    color: var(--tab-active);
}

/* ============================================
   GOLD CARDS GRID
   ============================================ */
.gold-cards-grid {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 20px;
    margin-top: 10px;
}

@media (max-width: 900px) {
    .gold-cards-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 600px) {
    .gold-cards-grid {
        grid-template-columns: 1fr;
    }
}

.gold-card {
    background: var(--bg-card);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--border-color);
    border-radius: var(--radius-card);
    padding: 22px 24px;
    box-shadow: var(--shadow-glass);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.gold-card:hover {
    box-shadow: var(--shadow-md);
    border-color: rgba(245, 158, 11, 0.12);
}

.gold-card .card-title {
    font-size: 1rem;
    margin-bottom: 16px;
}

.gold-card .form-group {
    margin-bottom: 12px;
}
.gold-card .form-group label {
    font-size: 0.65rem;
}
.gold-card input,
.gold-card select {
    padding: 10px 14px;
    font-size: 0.9rem;
    border-radius: 12px;
}
.gold-card .btn {
    padding: 10px 16px;
    font-size: 0.85rem;
    border-radius: 12px;
    margin-top: 4px;
}
.gold-card .result-box {
    padding: 14px 18px;
    margin-top: 12px;
}
.gold-card .result-value {
    font-size: 1.2rem;
}
.gold-card .result-detail-row {
    font-size: 0.8rem;
    padding: 4px 0;
}
.gold-card .result-detail-row .value.final {
    font-size: 1rem;
}

/* ============================================
   COMPARISON TABLE
   ============================================ */
.compare-table-wrap {
    overflow-x: auto;
    margin-top: 10px;
}

.compare-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
    min-width: 400px;
}

.compare-table th {
    background: var(--bg-input);
    padding: 14px 16px;
    text-align: center;
    font-weight: 700;
    color: var(--text-secondary);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    border-bottom: 2px solid var(--border-color);
}

.compare-table td {
    padding: 12px 16px;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
}

.compare-table tr:last-child td {
    border-bottom: none;
}

.compare-table .highlight-cell {
    font-weight: 700;
    color: var(--tab-active);
    font-size: 1.05rem;
}

.compare-table .positive-cell {
    color: var(--success);
}
.compare-table .negative-cell {
    color: var(--error);
}

/* ============================================
   TOAST
   ============================================ */
.toast-message {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    color: var(--text-primary);
    padding: 16px 32px;
    border-radius: 60px;
    display: flex;
    align-items: center;
    gap: 14px;
    font-size: 0.9rem;
    font-weight: 500;
    z-index: 9999;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.4s ease;
    direction: rtl;
    opacity: 0;
    pointer-events: none;
    min-width: 200px;
}

.toast-message.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
    pointer-events: all;
}

.toast-message.success {
    border-right: 4px solid var(--success);
}
.toast-message.success i {
    color: var(--success);
}
.toast-message.error {
    border-right: 4px solid var(--error);
}
.toast-message.error i {
    color: var(--error);
}
.toast-message.warning {
    border-right: 4px solid var(--warning);
}
.toast-message.warning i {
    color: var(--warning);
}

/* ============================================
   PURITY TOGGLE (برای صفحه طلا)
   ============================================ */
.purity-toggle {
    display: flex;
    gap: 8px;
    background: var(--bg-input);
    border-radius: 60px;
    padding: 4px;
    border: 2px solid var(--border-color);
    backdrop-filter: blur(8px);
}

.purity-btn {
    flex: 1;
    padding: 12px 24px;
    border: none;
    border-radius: 40px;
    font-weight: 700;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
    background: transparent;
    color: var(--text-secondary);
    font-family: var(--font);
}

.purity-btn.active {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: #fff;
    box-shadow: 0 4px 16px rgba(245, 158, 11, 0.25);
}

.purity-btn:hover:not(.active) {
    background: var(--bg-card);
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 700px) {
    .card {
        padding: 20px 18px;
    }
    .calc-tab {
        min-width: 50px;
        padding: 10px 12px;
        font-size: 0.7rem;
    }
    .calc-tab span {
        display: none;
    }
    .calc-tab i {
        font-size: 1.3rem;
    }
    .calc-title {
        font-size: 1.4rem;
    }
    .result-value {
        font-size: 1.4rem;
    }
    .calc-header {
        flex-direction: column;
        align-items: stretch;
        gap: 12px;
    }
    .header-left {
        flex-wrap: wrap;
    }
    .gold-cards-grid {
        grid-template-columns: 1fr;
    }
    .purity-btn {
        padding: 10px 16px;
        font-size: 0.8rem;
    }
}

@media (max-width: 400px) {
    body {
        padding: 12px;
    }
}

::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: var(--tab-active);
    border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
    background: #d97706;
}