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

:root {
    --bg:        #0b0f1a;
    --surface:   #111827;
    --border:    #1f2937;
    --accent:    #6366f1;
    --accent2:   #818cf8;
    --text:      #f1f5f9;
    --muted:     #64748b;
    --success:   #10b981;
    --error:     #ef4444;
}

body {
    min-height: 100vh;
    background: var(--bg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'Sarabun', 'Inter', sans-serif;
    overflow: hidden;
}

/* ===== Animated BG ===== */
.bg-grid {
    position: fixed; inset: 0; z-index: 0;
    background-image:
        linear-gradient(rgba(99,102,241,0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99,102,241,0.04) 1px, transparent 1px);
    background-size: 40px 40px;
}
.bg-glow {
    position: fixed; z-index: 0;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.18;
    animation: drift 12s ease-in-out infinite alternate;
}
.bg-glow.g1 { width: 500px; height: 500px; background: #6366f1; top: -150px; left: -100px; }
.bg-glow.g2 { width: 400px; height: 400px; background: #06b6d4; bottom: -100px; right: -80px; animation-delay: -6s; }

@keyframes drift {
    from { transform: translate(0, 0) scale(1); }
    to   { transform: translate(30px, 20px) scale(1.08); }
}

/* ===== Card ===== */
.card {
    position: relative; z-index: 1;
    width: 100%; max-width: 420px;
    margin: 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 44px 40px 40px;
    box-shadow: 0 24px 64px rgba(0,0,0,0.5);
    animation: slideUp .5s cubic-bezier(.16,1,.3,1) both;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(24px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ===== Logo ===== */
.logo-wrap {
    display: flex; align-items: center; gap: 12px;
    margin-bottom: 32px;
}
.logo-icon {
    width: 44px; height: 44px;
    background: linear-gradient(135deg, var(--accent), #a78bfa);
    border-radius: 12px;
    display: flex; align-items: center; justify-content: center;
    font-size: 20px; color: #fff;
    box-shadow: 0 4px 16px rgba(99,102,241,0.4);
}
.logo-text { line-height: 1.2; }
.logo-title { font-size: 16px; font-weight: 700; color: var(--text); letter-spacing: .3px; }
.logo-sub   { font-size: 12px; color: var(--muted); font-weight: 400; }

/* ===== Heading ===== */
.heading { margin-bottom: 28px; }
.heading h1 { font-size: 22px; font-weight: 700; color: var(--text); margin-bottom: 4px; }
.heading p  { font-size: 13px; color: var(--muted); }

/* ===== Form ===== */
.field { margin-bottom: 18px; }
.field label {
    display: block; font-size: 13px; font-weight: 600;
    color: #94a3b8; margin-bottom: 7px; letter-spacing: .3px;
}
.input-wrap {
    position: relative;
    display: flex;
    align-items: center;
}
.input-wrap .icon-left {
    position: absolute; left: 14px;
    color: var(--muted); font-size: 14px; pointer-events: none;
    transition: color .2s; z-index: 2;
}
.input-wrap input {
    width: 100%; padding: 12px 46px 12px 40px;
    background: #0b0f1a;
    border: 1px solid var(--border);
    border-radius: 10px;
    font-size: 15px; font-family: inherit;
    color: var(--text);
    outline: none;
    transition: border-color .2s, box-shadow .2s;
}
.input-wrap input::placeholder { color: #374151; }
.input-wrap input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(99,102,241,0.15);
}
.input-wrap:focus-within .icon-left { color: var(--accent2); }

.toggle-pw {
    position: absolute; right: 0;
    height: 100%;
    width: 44px;
    cursor: pointer; color: var(--muted); font-size: 14px;
    background: none; border: none;
    transition: color .2s;
    display: flex; align-items: center; justify-content: center;
    border-radius: 0 10px 10px 0;
}
.toggle-pw:hover { color: var(--accent2); }

/* ===== Error ===== */
.error-msg {
    display: none;
    background: rgba(239,68,68,0.1);
    border: 1px solid rgba(239,68,68,0.3);
    color: #fca5a5;
    font-size: 13px;
    padding: 10px 14px;
    border-radius: 8px;
    margin-bottom: 16px;
}
.error-msg.show { display: flex; align-items: center; gap: 8px; }

/* ===== Remember Me Checkbox ===== */
.remember-row {
    margin: -6px 0 18px;
}
.remember-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 13px;
    color: var(--muted);
    user-select: none;
}
.remember-label input[type="checkbox"] {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}
.checkmark {
    width: 18px;
    height: 18px;
    border: 1px solid var(--border);
    border-radius: 5px;
    background: var(--bg);
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all .15s;
}
.checkmark::after {
    content: '';
    width: 5px;
    height: 9px;
    border: solid #fff;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg) scale(0);
    transition: transform .15s;
    margin-bottom: 2px;
}
.remember-label input:checked ~ .checkmark {
    background: var(--accent);
    border-color: var(--accent);
}
.remember-label input:checked ~ .checkmark::after {
    transform: rotate(45deg) scale(1);
}
.remember-label:hover .checkmark {
    border-color: var(--accent2);
}

/* ===== Button ===== */
.btn-login {
    width: 100%; padding: 13px;
    background: linear-gradient(135deg, var(--accent), #7c3aed);
    color: #fff; border: none;
    border-radius: 10px;
    font-size: 15px; font-weight: 700;
    font-family: inherit;
    cursor: pointer;
    display: flex; align-items: center; justify-content: center; gap: 8px;
    box-shadow: 0 4px 16px rgba(99,102,241,0.35);
    transition: opacity .2s, transform .1s, box-shadow .2s;
    margin-top: 6px;
}
.btn-login:hover { opacity: .92; box-shadow: 0 6px 24px rgba(99,102,241,0.45); }
.btn-login:active { transform: scale(.98); }
.btn-login.loading { pointer-events: none; opacity: .7; }
.btn-login .spinner {
    display: none; width: 16px; height: 16px;
    border: 2px solid rgba(255,255,255,0.3);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin .6s linear infinite;
}
.btn-login.loading .spinner { display: block; }
.btn-login.loading .btn-text { display: none; }

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

@keyframes shakeError {
    0%,100% { transform: translateX(0); }
    20%      { transform: translateX(-6px); }
    40%      { transform: translateX(6px); }
    60%      { transform: translateX(-4px); }
    80%      { transform: translateX(4px); }
}

/* ===== Footer ===== */
.card-footer {
    margin-top: 28px; padding-top: 20px;
    border-top: 1px solid var(--border);
    text-align: center;
    font-size: 12px; color: var(--muted);
}
.card-footer span { color: #475569; }